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products and specifications discussed herein are subject to change by micron without notice. 09005aef8076894f 256mbddrx4x8x16_1.fm - rev. f 6/03 en 1 ?2003 micron technology, inc. 256mb: x4, x8, x16 ddr sdram double data rate (ddr) sdram mt46v64m4 ? 16 meg x 4 x 4 banks mt46v32m8 ? 8 meg x 8 x 4 banks mt46v16m16 ? 4 meg x 16 x 4 banks for the latest data sheet revi sions, please refer to the micron web site: www.micron.com/datasheets features ?v dd = +2.5v 0.2v, v dd q = +2.5v 0.2v bidirectional data strobe (dqs) transmitted/received with data, i.e., source-synch ronous data capture (x16 has two ? one per byte) internal, pipelined double data rate (ddr) architecture; two data accesses per clock cycle differential clock inputs (ck and ck#) commands entered on each positive ck edge dqs edge-aligned with data for reads; center-aligned with data for writes dll to align dq and dqs transitions with ck four internal banks for concurrent operation data mask (dm) for masking write data (x16 has two ? one per byte) programmable burst lengths: 2, 4, or 8 auto refresh and self refresh modes longer-lead tsop for improved reliability (ocpl) 2.5v i/o (sstl_2 compatible) concurrent auto precharge option supported t ras lockout supported ( t rap = t rcd) note: 1. contact micron for availability of lead-free products. 2. supports pc2700 modules with 2.5-3-3 timing. 3. supports pc2100 modules with 2-2-2 timing. 4. supports pc2100 modules with 2-3-3 timing. 5. supports pc2100 modules with 2.5-3-3 timing. 6. supports pc1600 modules with 2-2-2 timing. 7. cl=cas(read) latency. 8. minimum clock rate @ cl = 2 (-75e, -75z), @ cl = 2.5 (-6t, -6r, -75) options marking configuration 64 meg x 4 (16 meg x 4 x 4 banks) 64m4 32 meg x 8 (8 meg x 8 x 4 banks) 32m8 16 meg x 16 (4 meg x 16 x 4 banks) 16m16 plastic package ? ocpl 66-pin tsop tg 66-pin tsop (lead-free) 1 p plastic package 60-ball fbga (16mm x 9mm) fj 60-ball fbga (16mm x 9mm)(lead-free) 1 bj 60-ball fbga (14mm x 8mm) fg 60-ball fbga (14mm x 8mm) (lead-free) 1 bg timing ? cycle time 6ns @ cl = 2.5 (ddr333) 2 (fbga only) -6 6ns @ cl = 2.5 (ddr333) 2 (tsop only) -6r/-6t 7.5ns @ cl = 2 (ddr266) 3 -75e 7.5ns @ cl = 2 (ddr266a) 4 -75z 7.5ns @ cl = 2.5 (ddr266b) 5, 6 -75 self refresh standard none low-power self refresh l high-speed process enhancement standard none high speed h temperature rating standard (0 c to +70 c) none industrial temperature (-40 c to +85 c) it table 1: key timing parameters speed grade clock rate 7 data-out window 8 access window dqs?dq skew cl=2 cl=2.5 -6 133 mhz 167 mhz 2.1ns 0.7ns +0.40ns -6r/-6t 133 mhz 167 mhz 2.0ns 0.7ns +0.45ns -75e/-75z 133 mhz 133 mhz 2.5ns 0.75ns +0.5ns -75 100 mhz 133 mhz 2.5ns 0.75ns +0.5ns 64 meg x 4 32 meg x 8 16 meg x 16 configuration 16 meg x 4 x 4 banks 8 meg x 8 x 4 banks 4 meg x 16 x 4 banks refresh count 8k 8k 8k row addressing 8k (a0?a12) 8k (a0?a12) 8k (a0?a12) bank addressing 4 (ba0,ba1) 4 (ba0,ba1) 4 (ba0,ba1) column addressing 2k (a0?a9,a11) 1k (a0?a9) 512 (a0?a8) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 v ss dq15 v ss q dq14 dq13 v dd q dq12 dq11 v ss q dq10 dq9 v dd q dq8 nc v ss q udqs dnu v ref v ss udm ck# ck cke nc a12 a11 a9 a8 a7 a6 a5 a4 v ss x16 v dd dq0 v dd q dq1 dq2 vssq dq3 dq4 v dd q dq5 dq6 vssq dq7 nc v dd q ldqs nc v dd dnu ldm we# cas# ras# cs# nc ba0 ba1 a10/ap a0 a1 a2 a3 v dd x16 v ss dq7 v ss q nc dq6 v dd q nc dq5 v ss q nc dq4 v dd q nc nc v ss q dqs dnu v ref v ss dm ck# ck cke nc a12 a11 a9 a8 a7 a6 a5 a4 v ss x8 x4 v ss nc v ss q nc dq3 v dd q nc nc v ss q nc dq2 v dd q nc nc v ss q dqs dnu v ref v ss dm ck# ck cke nc a12 a11 a9 a8 a7 a6 a5 a4 v ss v dd dq0 v dd q nc dq1 v ss q nc dq2 v dd q nc dq3 v ss q nc nc v dd q nc nc v dd dnu nc we# cas# ras# cs# nc ba0 ba1 a10/ap a0 a1 a2 a3 v dd x8 x4 v dd nc v dd q nc dq0 v ss q nc nc v dd q nc dq1 v ss q nc nc v dd q nc nc v dd dnu nc we# cas# ras# cs# nc ba0 ba1 a10/ap a0 a1 a2 a3 v dd figure 1: pin assignment (top view) 66-pin tsop
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_1.fm - rev. f 6/03 en 2 ?2003 micron technology, inc. figure 2: 256mb ddr sdram part numbers general description the 256mb ddr sdram is a high-speed cmos, dynamic random-access memory containing 268,435,456 bits. it is internally configured as a quad- bank dram. the 256mb ddr sdram uses a double-data-rate architecture to achieve high-speed operation. the double data rate architecture is essentially a 2 n - prefetch architecture with an interface designed to transfer two data words per clock cycle at the i/o pins. a single read or write access for the 256mb ddr sdram effectively consists of a single 2 n -bit wide, one-clock-cycle data transfer at the internal dram core and two corresponding n -bit wide, one-half- clock-cycle data transfers at the i/o pins. a bidirectional data strobe (dqs) is transmitted externally, along with data, for use in data capture at the receiver. dqs is a strobe transmitted by the ddr sdram during reads and by the memory controller during writes. dqs is edge-aligned with data for reads and center-aligned with data for writes. the x16 offering has two data strobes, one for the lower byte and one for the upper byte. the 256mb ddr sdram operates from a differen- tial clock (ck and ck#); the crossing of ck going high and ck# going low will be referred to as the positive edge of ck. commands (address and control signals) are registered at every positive edge of ck. input data is registered on both edges of dqs, and output data is referenced to both edges of dqs, as well as to both edges of ck. read and write accesses to the ddr sdram are burst oriented; accesses start at a selected location and continue for a programmed number of locations in a programmed sequence. accesses begin with the regis- tration of an active command, which is then fol- lowed by a read or write command. the address bits registered coincident with the active command are used to select the bank and row to be accessed. the address bits registered coincident with the read or write command are used to select the bank and the starting column location for the burst access. the ddr sdram provides for programmable read or write burst lengths of 2, 4, or 8 locations. an auto precharge function may be enabled to provide a self- timed row precharge that is initiated at the end of the burst access. as with standard sdr sdrams, the pipelined, multibank architecture of ddr sdrams allows for concurrent operation, thereby effectively providing high bandwidth by hiding row precharge and activa- tion time. an auto refresh mode is provided, along with a power-saving power-down mode. all inputs are com- patible with the jedec standard for sstl_2. all full drive option outputs are sst l_2, class ii-compatible. note: 1. the functionality and the timing specifica- tions discussed in this data sheet are for the dll-enabled mode of operation. 2. throughout the data sheet, the various fig- ures and text refer to dqs as ?dq.? the dq term is to be interpreted as any and all dq collectively, unless specifically stated other- wise. additionally, the x16 is divided into two bytes, the lower byte and upper byte. for the lower byte (dq0 through dq7) dm refers to ldm and dqs refers to ldqs. for the upper byte (dq8 through dq15) dm refers to udm and dqs refers to udqs. 3. complete functionality is described throughout the document and any page or diagram may have been simplified to con- vey a topic and may not be inclusive of all requirements. 4. any specific requirement takes precedence over a general statement. - l h special options standard low power high-speed process configuration mt46v package speed special options temperature configuration 64 meg x 4 32 meg x 8 16 meg x 16 64m4 32m8 16m16 package 400-mil tsop 400-mil tsop (lead-free) 16x9 fbga 16x9 fbga (lead-free) 14x9 fbga 14x9 fbga (lead-free) tg p fj bj fg bg speed grade t ck = 6ns, cl = 2.5 t ck = 6ns, cl = 2.5 t ck = 6ns, cl = 2.5 t ck = 7.5ns, cl = 2 t ck = 7.5ns, cl = 2 t ck = 7.5ns, cl = 2.5 -6 -6t -6r -75e -75z -75 it operating temp standard industrial temp example part number: m t46v16m16tg-75z h
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16toc.fm - rev. f 6/03 en 3 ?2003 micron technology, inc. table of contents features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 general description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 register definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 mode register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 burst length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 burst type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 read latency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 operating mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 extended mode register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 output drive strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 dll enable/disable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 deselect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 no operation (nop). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 load mode register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 active . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 read . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 precharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 auto precharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 burst terminate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18 auto refresh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18 self refresh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18 operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 bank/row activation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 reads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 writes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29 precharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40 power-down (cke not active) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40 absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46 notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59 data sheet designation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .80
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16lof.fm - rev. f 6/03 en 4 ?2003 micron technology, inc. list of figures figure 1: pin assignment (top view) 66-pin tsop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 figure 2: 256mb ddr sdram part numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 figure 3: functional block diagram: 64 meg x 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 figure 4: functional block diagram: 32 meg x 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 figure 5: functional block diagram: 16 meg x 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 figure 6: 60-ball fbga ball assignment (top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 figure 7: mode register definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 figure 8: cas latency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 figure 9: extended mode register definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 figure 10: activating a specific row in a specific bank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 figure 11: example: meeting t rcd ( t rrd) min when 2 < t rcd ( t rrd) min/ t ck 3 . . . . . . . . . . . . . . . . . . . . . .19 figure 12: read command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21 figure 13: read burst. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22 figure 14: consecutive read bursts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23 figure 15: nonconsecutive read bursts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24 figure 16: random read accesses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25 figure 17: terminating a read burst . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26 figure 18: read to write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27 figure 19: read to precharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28 figure 20: write command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29 figure 21: write burst. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30 figure 22: consecutive write to write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31 figure 23: nonconsecutive write to write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32 figure 24: random write cycles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33 figure 25: write to read - uninterrupting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34 figure 26: write to read ? interrupting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 figure 27: write to read ? odd number of data, interrupting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36 figure 28: write to precharge - uninterrupting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37 figure 29: write to precharge ? interrupting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 figure 30: write to precharge ? odd number of data ? interrupting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39 figure 31: precharge command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40 figure 32: power-down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41 figure 33: input voltage waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47 figure 34: sstl_2 clock input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48 figure 35: derating data valid window ( t qh - t dqsq) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60 figure 36: full drive pull-down characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61 figure 37: full drive pull-up characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61 figure 38: reduced drive pull-down characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62 figure 39: reduced drive pull-up characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62 figure 40: x4, x8 data output timing ? t dqsq, t qh, and data valid window . . . . . . . . . . . . . . . . . . . . . . . . . . . .65 figure 41: x16 data output timing ? t dqsq, t qh, and data valid window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66 figure 42: data output timing ? t ac and t dqsck . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67 figure 43: data input timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68 figure 44: initialize and load mode registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69 figure 45: power-down mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70 figure 46: auto refresh mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71 figure 47: self refresh mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72 figure 48: bank read - without auto precha rge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73 figure 49: bank read - with auto precharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74 figure 50: bank write - without auto precharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75 figure 51: bank write - with auto precharg e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .76 figure 52: write ? dm operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77 figure 53: 66-pin plastic tsop (400 mil). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .78 figure 54: 60-ball fbga (16 x 9mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .79 figure 55: 60-ball fbga (14 x 8mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .80
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16lot.fm - rev. f 6/03 en 5 ?2003 micron technology, inc. list of tables table 1: key timing parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 table 2: ball/pin descriptions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 table 3: reserved nc balls and pins 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 table 4: burst definition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 table 5: cas latency (cl) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 table 6: truth table ? commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 table 7: truth table ? dm operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 table 8: truth table ? cke. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41 table 9: truth table ? current state bank n ? command to bank n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42 table 10: truth table ? current state bank n ? command to bank m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44 table 11: dc electrical characteristics and operating conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46 table 12: ac input operating conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46 table 13: clock input operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48 table 14: capacitance (x4, x8 tsop) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49 table 15: capacitance (x4, x8 fbga) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49 table 16: capacitance (x16 tsop) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50 table 17: capacitance (x16 fbga) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50 table 18: i dd specifications and conditions (x4, x8; -6/-6r/-6t/-75e) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51 table 19: i dd specifications and conditions (x4, x8; -75z/-75) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52 table 20: i dd specifications and conditions (x16; -6/-6r/-6t/-75e) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53 table 21: i dd specifications and conditions (x16; -75z/-75) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54 table 22: i dd test cycle times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55 table 23: electrical characteristics and recommended ac operating conditions (-6/-6t/-6r/-75e) . . . . . .56 table 24: electrical characteristics and recommended ac op erating conditions (-75z/-75) . . . . . . . . . . . . .57 table 25: input slew rate derating values for addresses and comma nds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58 table 26: input slew rate derating values for dq, dqs, and dm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58 table 27: normal output drive characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63 table 28: reduced output drive characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 6 ?2003 micron technology, inc. figure 3: functional block diagram: 64 meg x 4 13 ras# cas# row- address mux ck cs# we# ck# control logic column- address counter/ latch mode registers 11 command decode a0-a12, ba0, ba1 cke 13 address register 15 1024 (x8) 8192 i/o gating dm mask logic column decoder bank0 memory array (8,192 x 1,024 x 8) bank0 row- address latch & decoder 8192 sense amplifiers bank control logic 15 bank1 bank2 bank3 13 10 1 2 2 refresh counter 4 4 4 1 input registers 1 1 1 1 rcvrs 1 8 8 2 8 clk out data dqs mask data ck ck col0 clk in drvrs dll mux dqs generator 4 4 4 4 4 8 dq0? dq3 dqs dm 1 read latch write fifo & drivers col0
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 7 ?2003 micron technology, inc. figure 4: functional block diagram: 32 meg x 8 13 ras# cas# row- address mux ck cs# we# ck# control logic column- address counter/ latch mode registers 10 command decode a0-a12, ba0, ba1 cke 13 address register 15 512 (x16) 8192 i/o gating dm mask logic column decoder bank0 memory array (8192 x 512 x 16) bank0 row- address latch & decoder 8192 sense amplifiers bank control logic 15 bank1 bank2 bank3 13 9 2 2 refresh counter 8 8 8 1 input registers 1 1 1 1 rcvrs 1 16 16 2 16 clk out data dqs mask data ck ck clk in drvrs dll mux dqs generator 8 8 8 8 8 16 dq0? dq7 dqs 1 read latch write fifo & drivers 1 col0 col0 dm
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 8 ?2003 micron technology, inc. figure 5: functional block diagram: 16 meg x 16 13 ras# cas# row- address mux ck cs# we# ck# control logic column- address counter/ latch mode registers 9 command decode a0-a12, ba0, ba1 cke 13 address register 15 256 (x32) 8192 i/o gating dm mask logic column decoder bank0 memory array (8,192 x 256 x 32) bank0 row- address latch & decoder 8192 sense amplifiers bank control logic 15 bank1 bank2 bank3 13 8 2 2 refresh counter 16 16 16 2 input registers 2 2 2 2 rcvrs 2 32 32 4 32 clk out data dqs mask data ck ck clk in drvrs dll mux dqs generator 16 16 16 16 16 32 dq0 - dq15 ldqs udqs 2 read latch write fifo & drivers 1 col0 col0 ldm, udm
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 9 ?2003 micron technology, inc. table 2: ball/pin descriptions fbga numbers tsop numbers symbol type description g2, g3 45, 46 ck, ck# input clock: ck and ck# are differential clock inputs. all address and control input signals are sampled on the crossing of the positive edge of ck and the negative edge of ck#. output data (dq and dqs) is referenced to the crossings of ck and ck#. h3 44 cke input clock enable: cke high activates and cke low deactivates the internal clock, input buffers, and output drivers. taking cke low provides precharge power-down and self refresh operations (all banks idle) or active power-down (row active in any bank). cke is synchronous for power-down entry and exit and for self refresh entry. cke is asynchronous for self refresh exit and for disabling the outputs. cke must be maintained high throughout read and write accesses. input buffers (excluding ck, ck#, and cke) are disabled during power- down. input buffers (excluding cke) are disabled during self refresh. cke is an sstl_2 input but will detect an lvcmos low level after v dd is applied and until cke is first brought high, after which it becomes an sstl_2 input only. h8 24 cs# input chip select: cs# enables (registered low) and disables (registered high) the command decoder. all commands are masked when cs# is registered high. cs# provides for external bank selection on systems with multiple banks. cs# is considered part of the command code. h7, g8, g7 23, 22, 21 ras#, cas#, we# input command inputs: ras#, cas#, and we# (along with cs#) define the command being entered. 3f 47 dm input input data mask: dm is an input mask signal for write data. input data is masked when dm is sampled high along with that input data during a write access. dm is sampled on both edges of dqs. although dm pins are input-only, the dm loading is designed to match that of dq and dqs pins. for the x16, ldm is dm for dq0? dq7 and udm is dm for dq8?dq15. pin 20 is a nc on x4 and x8. f7, 3f 20, 47 ldm, udm j8, j7 26, 27 ba0, ba1 input bank address inputs: ba0 and ba1 define to which bank an active, read, write, or precharge command is being applied. k7, l8, l7, m8, m2, l3, l2, k3, k2, j3, k8, j2, h2 29, 30, 31, 32, 35, 36, 37, 38, 39, 40, 28 41, 42 a0, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12 input address inputs: provide the row ad dress for active commands, and the column address and auto precharge bit (a10) for read/write commands, to select one location out of the memory array in the respective bank. a10 sampled during a precharge command determines whether the precharge applies to one bank (a10 low, bank selected by ba0, ba1) or all banks (a10 high). the address inputs also provide the op-code during a mode register set command. ba0 and ba1 define which mode register (mode register or extended mode register) is loaded during the load mode register command. a8, b9, b7, c9, c7, d9, d7, e9, e1, d3, d1, c3, c1, b3, b1, a2 2, 4, 5, 7, 8, 10, 11, 13, 54, 56, 57, 59, 60, 62, 63, 65 dq0?dq2 dq3?dq5 dq6?dq8 dq9?dq11 dq12?dq14 dq15 i/o data input/output: data bus for x16 . (dq4?dq15 are nc for the x4) (dq8?dq16 are nc for the x8)
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 10 ?2003 micron technology, inc. note: 1. nc pins not listed may also be reserved for other uses now or in the future. this table simply defines specific nc pins deemed to be of importance. a8, b7, c7, d7, d3, c3, b3, a2 2, 5, 8, 11, 56, 59, 62, 65 dq0?dq2 dq3?dq5 dq6, dq7 i/o data input/output: data bus for x8 . (dq4?dq7 are nc for the x4) b7, d7, d3, b3 5, 11, 56, 62 dq0?dq2 dq3 i/o data input/output: data bus for x4 . e3 e7 e3 51 16 51 dqs ldqs udqs i/o data strobe: output with read data, input with write data. dqs is edge-aligned with read data, centered in write data. it is used to capture data. for the x16, ldqs is dqs for dq0?dq7 and udqs is dqs for dq8?dq15. pin 16 (e7) is nc on x4 and x8. 14, 17, 25, 43, 53 nc ? no connect: these pins should be left unconnected. f9 19, 50 dnu ? do not use: must float to minimize noise on v ref . b2, d2, c8, e8, a9 3, 9, 15, 55, 61 v dd q supply dq power supply: +2.5v 0.2v. isolated on the die for improved noise immunity. a1, c2, e2, b8, d8 6, 12, 52, 58, 64 v ss q supply dq ground: isolated on the die for improved noise immunity. f8, m7, a7 1, 18, 33 v dd supply power supply: +2.5v 0.2v. a3, f2, m3 34, 48, 66 v ss supply ground. f1 49 v ref supply sstl_2 reference voltage. table 2: ball/pin descriptions (continued) fbga numbers tsop numbers symbol type description table 3: reserved nc balls and pins 1 fbga numbers tsop numbers symbol type description f9 17 a13 i address input a13 for 1gb devices. dnu for fbga.
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 11 ?2003 micron technology, inc. figure 6: 60-ball fbga ball assignment (top view) v ss q dq14 dq12 dq10 dq8 v ref dq15 v dd q v ss q v dd q v ss q v ss ck a12 a11 a8 a6 a4 v ss dq13 dq11 dq9 udqs udm ck# cke a9 a7 a5 v ss v dd dq2 dq4 dq6 ldqs ldm we# ras# ba1 a0 a2 v dd dq0 v ss q v dd q v ss q v dd q v dd cas# cs# ba0 a10 a1 a3 v dd q dq1 dq3 dq5 dq7 dnu x16 (top view) v ss q nc nc nc nc v ref nc v dd q v ss q v dd q v ss q v ss ck a12 a11 a8 a6 a4 v ss dq3 nc dq2 dqs dm ck# cke a9 a7 a5 v ss v dd dq0 nc dq1 nc nc we# ras# ba1 a0 a2 v dd nc v ss q v dd q v ss q v dd q v dd cas# cs# ba0 a10 a1 a3 v dd q nc nc nc nc dnu x4 (top view) v ss q nc nc nc nc v ref dq7 v dd q v ss q v dd q v ss q v ss ck a12 a11 a8 a6 a4 v ss dq6 dq5 dq4 dqs dm ck# cke a9 a7 a5 v ss v dd dq1 dq2 dq3 nc nc we# ras# ba1 a0 a2 v dd dq0 v ss q v dd q v ss q v dd q v dd cas# cs# ba0 a10 a1 a3 v dd q nc nc nc nc dnu x8 (top view) a 12 3456789 b c d e f g h j k l m a 12 3456789 b c d e f g h j k l m a 12 3456789 b c d e f g h j k l m
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 12 ?2003 micron technology, inc. functional description the 256mb ddr sdram is a high-speed cmos, dynamic random-access memory containing 268,435,456 bits. the 256mb ddr sdram is internally configured as a quad-bank dram. the 256mb ddr sdram uses a double data rate architecture to achieve high-speed operation. the double data rate architecture is essentially a 2 n - prefetch architecture, with an interface designed to transfer two data words per clock cycle at the i/o pins. a single read or write access for the 256mb ddr sdram consists of a single 2 n -bit wide, one-clock- cycle data transfer at the internal dram core and two corresponding n -bit wide, one-half-clock-cycle data transfers at the i/o pins. read and write accesses to the ddr sdram are burst oriented; accesses start at a selected location and continue for a programmed number of locations in a programmed sequence. accesses begin with the regis- tration of an active command, which is then fol- lowed by a read or write command. the address bits registered coincident with the active command are used to select the bank and row to be accessed (ba0, ba1 select the bank; a0?a12 select the row). the address bits registered coincident with the read or write command are used to select the starting col- umn location for the burst access. prior to normal operation, the ddr sdram must be initialized. the following sections provide detailed information covering device initialization, register def- inition, command descriptions, and device operation. initialization ddr sdrams must be powered up and initialized in a predefined manner. operational procedures other than those specified may result in undefined opera- tion. power must first be applied to v dd and v dd q simultaneously, and then to v ref (and to the system v tt ). v tt must be applied after v dd q to avoid device latch-up, which may cause permanent damage to the device. v ref can be applied any time after v dd q but is expected to be nominally coincident with v tt . except for cke, inputs are not recognized as valid until after v ref is applied. cke is an sstl_2 input but will detect an lvcmos low level after v dd is applied. after cke passes through v ih , it will transition to a sstl_2 signal and remain as such until power is cycled. maintaining an lvcmos low level on cke during power-up is required to ensure that the dq and dqs outputs will be in the high-z state, where they will remain until driven in normal operation (by a read access). after all power supply and reference voltages are stable, and the clock is stable, the ddr sdram requires a 200s delay prior to applying an executable command. once the 200s delay has been satisfied, a dese- lect or nop command should be applied and cke should be brought high. following the nop com- mand, a precharge all command should be applied. next a load mode register command should be issued for the extended mode register (ba1 low and ba0 high) to enable the dll, followed by another load mode register command to the mode register (ba0/ba1 both low) to reset the dll and to program the operating parameters. two hun- dred clock cycles are required between the dll reset and any read command. a precharge all com- mand should then be applied, placing the device in the all banks idle state. once in the idle state, two auto refresh cycles must be performed ( t rfc must be satisfied). addition- ally, a load mode register command for the mode register with the reset dll bit deactivated (i.e., to pro- gram operating parameters without resetting the dll) is required. following these requirements, the ddr sdram is ready for normal operation. register definition mode register the mode register is used to define the specific mode of operation of the ddr sdram. this definition includes the selection of a burst length, a burst type, a cas latency, and an operating mode, as shown in figure 7 on page 13. the mode register is programmed via the mode register set command (with ba0 = 0 and ba1 = 0) and will retain the stored information until it is programmed again or the device loses power (except for bit a8, which is self-clearing). reprogramming the mode register will not alter the contents of the memory, provided it is performed cor- rectly. the mode register must be loaded (reloaded) when all banks are idle and no bursts are in progress, and the controller must wait the specified time before initiating the subsequent operation. violating either of these requirements will result in unspecified opera- tion. mode register bits a0?a2 specify the burst length; a3 specifies the type of burst (sequential or inter- leaved); a4?a6 specify the cas latency; and a7?a12 specify the operating mode.
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 13 ?2003 micron technology, inc. burst length read and write accesses to the ddr sdram are burst oriented, with the burst length being program- mable, as shown in figure 7. the burst length deter- mines the maximum number of column locations that can be accessed for a given read or write command. burst lengths of 2, 4, or 8 locations are available for both the sequential and the interleaved burst types. reserved states should not be used, as unknown operation or incompatibility with future versions may result. when a read or write command is issued, a block of columns equal to the burst length is effectively selected. all accesses for that burst take place within this block, meaning that the burst will wrap within the block if a boundary is reached. the block is uniquely selected by a1?a i when the burst length is set to two, by a2?a i when the burst length is set to four, and by a3-a i when the burst length is set to eight (where a i is the most significant column address bit for a given configuration). the remaining (least significant) address bit(s) is (are) used to select the starting loca- tion within the block. the programmed burst length applies to both read and write bursts. burst type accesses within a given burst may be programmed to be either sequential or interleaved; this is referred to as the burst type and is selected via bit m3. the ordering of accesses within a burst is deter- mined by the burst length, the burst type, and the starting column address, as shown in table4, burst definition, on page 14. figure 7: mode register definition operating mode normal operation normal operation/reset dll all other states reserved 0 1 - 0 0 - 0 0 - 0 0 - 0 0 - 0 0 - valid valid - 0 1 burst type sequential interleaved cas latency reserved reserved 2 reserved reserved reserved 2.5 reserved burst length cas latency bt 0* a9 a7 a6 a5 a4 a3 a8 a2 a1 a0 mode register (mx) address bus 9 7 654 3 8 2 1 0 m3 m4 0 1 0 1 0 1 0 1 m5 0 0 1 1 0 0 1 1 m6 0 0 0 0 1 1 1 1 m6-m0 m8 m7 operating mode a10 a12 a11 ba0 ba1 10 11 12 13 0* 14 * m14 and m13 (ba1 and ba0) must be ?0, 0? to select the base mode register (vs. the extended mode register). m9 m10 m12 m11 burst length reserved 2 4 8 reserved reserved reserved reserved m0 0 1 0 1 0 1 0 1 m1 0 0 1 1 0 0 1 1 m2 0 0 0 0 1 1 1 1
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 14 ?2003 micron technology, inc. note: 1. whenever a boundary of the block is reached within a given sequence above, the following access wraps within the block. 2. for a burst length of two, a1 ? a i select the two-data- element block; a0 selects the first access within the block. 3. for a burst length of four, a2 ? a i select the four-data- element block; a0 ? a1 select the first access within the block. 4. for a burst length of eight, a3 ? a i select the eight-data- element block; a0 ? a2 select the first access within the block. read latency the read latency is the delay, in clock cycles, between the registration of a read command and the availability of the first bit of output data. the latency can be set to 2 or 2.5 clocks, as shown in figure 8. if a read command is registered at clock edge n , and the latency is m clocks, the data will be available nominally coincident with clock edge n + m . table 5, cas latency (cl), on page 14 indicates the operating frequencies at which each cas latency setting can be used. reserved states should not be used, as unknown operation or incompatibility with future versions may result. figure 8: cas latency operating mode the normal operating mode is selected by issuing a mode register set command with bits a7?a12 each set to zero, and bits a0?a6 set to the desired val- ues. a dll reset is initiated by issuing a mode regis- ter set command with bits a7 and a9?a12 each set to zero, bit a8 set to one, and bits a0?a6 set to the desired values. although not required by the micron device, jedec specifications recommend when a load mode register command is issued to reset the dll, it should always be followed by a load mode register command to select normal operat- ing mode. table 4: burst definition burst length starting column address order of accesses within a burst type= sequential type= interleaved 2a0 00-1 0-1 11-0 1-0 4a1a0 0 0 0-1-2-3 0-1-2-3 0 1 1-2-3-0 1-0-3-2 1 0 2-3-0-1 2-3-0-1 1 1 3-0-1-2 3-2-1-0 8a2a1a0 0 0 0 0-1-2-3-4-5-6-7 0-1-2-3-4-5-6-7 0 0 1 1-2-3-4-5-6-7-0 1-0-3-2-5-4-7-6 0 1 0 2-3-4-5-6-7-0-1 2-3-0-1-6-7-4-5 0 1 1 3-4-5-6-7-0-1-2 3-2-1-0-7-6-5-4 1 0 0 4-5-6-7-0-1-2-3 4-5-6-7-0-1-2-3 1 0 1 5-6-7-0-1-2-3-4 5-4-7-6-1-0-3-2 1 1 0 6-7-0-1-2-3-4-5 6-7-4-5-2-3-0-1 1 1 1 7-0-1-2-3-4-5-6 7-6-5-4-3-2-1-0 table 5: cas latency (cl) speed allowable operating clock frequency (mhz) cl = 2 cl = 2.5 -6/-6r/-6t 75 f 133 75 f 167 -75e 75 f 133 75 f 133 -75z 75 f 133 75 f 133 -75 75 f 100 75 f 133 ck ck# command dq dqs cl = 2 read nop nop nop read nop nop nop burst length = 4 in the cases shown shown with nominal t ac, t dqsck, and t dqsq ck ck# command dq dqs cl = 2.5 t0 t1 t2 t2n t3 t3n t0 t1 t2 t2n t3 t3n don?t care transitioning data
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 15 ?2003 micron technology, inc. all other combinations of values for a7?a12 are reserved for future use and/or test modes. test modes and reserved states should not be used, as unknown operation or incompatibility with future versions may result. extended mode register the extended mode register controls functions beyond those controlled by the mode register; these additional functions are dll enable/disable and out- put drive strength. these functions are controlled via the bits shown in figure 9. the extended mode register is programmed via the load mode register com- mand to the mode register (with ba0 = 1 and ba1 = 0) and will retain the stored information until it is pro- grammed again or the device loses power. the enabling of the dll should always be followed by a load mode register command to the mode regis- ter (ba0/ba1 both low) to reset the dll. the extended mode register must be loaded when all banks are idle and no bursts are in progress, and the controller must wait the specified time before initiat- ing any subsequent operation. violating either of these requirements could result in unspecified operation. output drive strength the normal drive strength for all outputs are speci- fied to be sstl_2, class ii. the x16 supports a pro- grammable option for reduced drive. this option is intended for the support of the lighter load and/or point-to-point environments. the selection of the reduced drive strength will alter the dq pins and dqs pins from sstl_2, class ii drive strength to a reduced drive strength, which is approximately 54 percent of the sstl_2, class ii drive strength. dll enable/disable when the part is running without the dll enabled, device functionality may be altered. the dll must be enabled for normal operation. dll enable is required during power-up initialization and upon returning to normal operation after having disabled the dll for the purpose of debug or evaluation. (when the device exits self refresh mode, the dll is enabled automati- cally.) any time the dll is enabled, 200 clock cycles must occur before a read command can be issued. figure 9: extende d mode register definition note: 1. e14 and e13 (ba1 and ba0) must be ?0, 1? to select the extended mode register vs. the base mode register. 2. the reduced drive strength option is not supported on the x4 and x8 versions; it is only available on the x16 version. 3. the qfc# option is not supported. operating mode reserved reserved 0 ? 0 ? valid ? 0 1 dll enable disable dll 1 1 0 1 a9 a7 a6 a5 a4 a3 a8 a2 a1 a0 extended mode register (ex) address bus 9 7 654 3 8 2 1 0 e0 0 1 drive strength normal reduced e1 2 e2 3 e0 e1, operating mode a10 a11 a12 ba1 ba0 10 11 12 13 14 e3 e4 0 ? 0 ? 0 ? 0 ? 0 ? e6 e5 e7 e8 e9 0 ? 0 ? e10 e11 0 ? e12 ds 0 ?
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 16 ?2003 micron technology, inc. commands table 6 and table 7 provide a quick reference of available commands, followed by a description of each command. two additional truth tables, table 9 on page 42, and table 10 on page 44, appear following the operation section, provide current state/next state information. note: 1. cke is high for all commands shown except self refresh. 2. ba0 ? ba1 select either the mode register or the extended mode register (ba0 = 0, ba1 = 0 select the mode register; ba0 = 1, ba1 = 0 select extended mode register; other combinations of ba0 ? ba1 are reserved). a0-a12 provide the op- code to be written to the selected mode register. 3. ba0 ? ba1 provide bank address and a0?a12 provide row address. 4. ba0 ? ba1 provide bank address; a0 ? a i provide column address, (where i = 8 for x16, i = 9 for x8, and i = 9,11 for x4) a10 high enables the auto precharge feature (nonpersistent ); and a10 low disables the auto precharge feature. 5. a10 low: ba0 ? ba1 determine which bank is precharged. a10 high: all banks are precharged and ba0 ? ba1 are ?don?t care.? 6. this command is auto refresh if cke is high, self refresh if cke is low. 7. internal refresh counter controls row addressing; within the self refresh m ode, all inputs and i/os are ?don?t care? except for cke. 8. applies only to read bursts with auto precharge disabled; this command is undefined (and should not be used) for read bursts with auto precharge enabled and for write bursts. 9. deselect and nop are functionally interchangeable. note: 1. used to mask write data; provided coincident with the corresponding data. table 6: truth table ? commands note 1 applies to all commands name (function) cs# ras# cas# we# addr notes deselect (nop) hxxx x 9 no operation (nop) lhhh x 9 active (select bank and activate row) l l h h bank/row 3 read (select bank and column, and start read burst) l h l h bank/col 4 write (select bank and column, and start write burst) l h l l bank/col 4 burst terminate lhhl x 8 precharge (deactivate row in bank or banks) l l h l code 5 auto refresh or self refresh (enter self refresh mode) lllh x 6, 7 load mode register llllop-code2 table 7: truth table ? dm operation note 1 applies to all commands name (function) dm dq write enable l valid write inhibit hx
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 17 ?2003 micron technology, inc. deselect the deselect function (cs# high) prevents new commands from being executed by the ddr sdram. the ddr sdram is effectively deselected. operations already in progress are not affected. no operation (nop) the no operation (nop) command is used to instruct the selected ddr sdram to perform a nop (cs# is low with ras#, cas#, and we# are high). this prevents unwanted commands from being regis- tered during idle or wait states. operations already in progress are not affected. load mode register the mode registers are loaded via inputs a0?a12. see mode register descriptions in the register defini- tion section on page 12. the load mode register command can only be issued when all banks are idle, and a subsequent executable command cannot be issued until t mrd is met. active the active command is used to open (or activate) a row in a particular bank for a subsequent access. the value on the ba0, ba1 inputs selects the bank, and the address provided on inputs a0?a12 selects the row. this row remains active (or open) for accesses until a precharge command is issued to that bank. a pre- charge command must be issued before opening a different row in the same bank. read the read command is used to initiate a burst read access to an active row. the value on the ba0, ba1 inputs selects the bank, and the address provided on inputs a0?a i (where i = 8 for x16, 9 for x8, or 9, 11 for x4) selects the starting column location. the value on input a10 determines whether or not auto precharge is used. if auto precharge is selected, the row being accessed will be precharged at the end of the read burst; if auto precharge is not selected, the row will remain open for subsequent accesses. write the write command is used to initiate a burst write access to an active row. the value on the ba0, ba1 inputs selects the bank, and the address provided on inputs a0?a i (where i = 8 for x16, 9 for x8, or 9, 11 for x4) selects the starting column location. the value on input a10 determines whether or not auto precharge is used. if auto precharge is selected, the row being accessed will be precharged at the end of the write burst; if auto precharge is not selected, the row will remain open for subsequent accesses. input data appearing on the dq is written to the memory array subject to the dm input logic level appearing coinci- dent with the data. if a given dm signal is registered low, the corresponding data will be written to mem- ory; if the dm signal is registered high, the corre- sponding data inputs will be ignored and a write will not be executed to that byte/column location. precharge the precharge command is used to deactivate the open row in a particular bank or the open row in all banks. the bank(s) will be available for a subsequent row access a specified time ( t rp) after the precharge command is issued, except in the case of concurrent auto precharge, where a read or write command to a different bank is allowed as long as it does not inter- rupt the data transfer in the current bank and does not violate any other timing parameters. input a10 deter- mines whether one or all banks are to be precharged, and in the case where only one bank is to be pre- charged, inputs ba0, ba1 select the bank. otherwise, ba0, ba1 are treated as ?don?t care.? once a bank has been precharged, it is in the idle state and must be activated prior to any read or write commands being issued to that bank. a precharge command will be treated as a nop if there is no open row in that bank (idle state) or if the previously open row is already in the process of precharging. auto precharge auto precharge is a feature that performs the same individual-bank precharge function described above, but without requiring an explicit command. this is accomplished by using a10 to enable auto precharge in conjunction with a specific read or write com- mand. a precharge of the bank/row that is addressed with the read or write command is automatically performed upon completion of the read or write burst. auto precharge is nonpersistent in that it is either enabled or disabled for each individual read or write command. this device supports concurrent auto precharge if the command to the other bank does not interrupt the data transfer to the current bank. auto precharge ensures that the precharge is initi- ated at the earliest valid stage within a burst. this earli- est valid stage is determined as if an explicit precharge command was issued at the earliest pos- sible time, without violating t ras (min), as described
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 18 ?2003 micron technology, inc. for each burst type in the operation section of this data sheet. the user must not issue another command to the same bank until the precharge time ( t rp) is completed. burst terminate the burst terminate command is used to trun- cate read bursts (with auto precharge disabled). the most recently registered read command prior to the burst terminate command will be truncated, as shown in the operation section of this data sheet. the open page, which the read burst was terminated from, remains open. auto refresh auto refresh is used during normal operation of the ddr sdram and is analogous to cas#-before- ras# (cbr) refresh in fpm/edo drams. this com- mand is nonpersistent, so it must be issued each time a refresh is required. all banks must be idle before an auto refresh command is issued. the addressing is generated by the internal refresh controller. this makes the address bits a ?don?t care? during an auto refresh command. the 256mb ddr sdram requires auto refresh cycles at an average interval of 7.8125s (maximum). to allow for improved efficiency in scheduling and switching between tasks, some flexibility in the abso- lute refresh interval is provided. a maximum of eight auto refresh commands can be posted to any given ddr sdram, meaning that the maximum abso- lute interval between any auto refresh command and the next auto refresh command is 9 x 7.8125s (70.3s). note, the jedec specification only allows 8 x 7.8125s, thus the micron specification exceeds the jedec requirement by one clock. this maximum absolute interval is to allow future support for dll updates internal to the ddr sdram to be restricted to auto refresh cycles, without allowing excessive drift in t ac between updates. although not a jedec requirement, to provide for future functionalities, cke must be active (high) dur- ing the auto refresh period. the auto refresh period begins when the auto refresh command is regis- tered and ends t rfc later. self refresh the self refresh command can be used to retain data in the ddr sdram, even if the rest of the system is powered down. when in the self refresh mode, the ddr sdram retains data without external clocking. the self refresh command is initiated like an auto refresh command except cke is disabled (low). the dll is automatically disabled upon enter- ing self refresh and is automatically enabled upon exiting self refresh. (a dll reset and 200 clock cycles must then occur before a read command can be issued.) input signals except cke are ?don?t care? during self refresh. v ref voltage is also required for the full duration of the self refresh. the procedure for exiting self refresh requires a sequence of commands. first, ck and ck# must be stable prior to cke going back high. once cke is high, the ddr sdram must have nop commands issued for t xsnr because time is required for the com- pletion of any internal refresh in progress. a simple algorithm for meeting both refresh and dll require- ments is to apply nops for t xsnr time, then a dll reset and nops for 200 additional clock cycles before applying any other command.
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 19 ?2003 micron technology, inc. operations bank/row activation before any read or write commands can be issued to a bank within the ddr sdram, a row in that bank must be ?opened.? this is accomplished via the active command, which selects both the bank and the row to be activated, as shown in figure 10. after a row is opened with an active command, a read or write command may be issued to that row, subject to the t rcd specification. t rcd (min) should be divided by the clock period and rounded up to the next whole number to determine the earliest clock edge after the active command on which a read or write command can be entered. for example, a t rcd specification of 20ns with a 133 mhz clock (7.5ns period) results in 2.7 clocks rounded to 3. this is reflected in figure 11, which covers any case where 2 < t rcd (min)/ t ck 3. (figure 11 also shows the same case for t rrd; the same procedure is used to convert other specification limits from time units to clock cycles.) a subsequent active command to a different row in the same bank can only be issued after the previous active row has been ?closed? (precharged). the mini- mum time interval between successive active com- mands to the same bank is defined by t rc. a subsequent active command to another bank can be issued while the first bank is being accessed, which results in a reduction of total row-access over- head. the minimum time interval between successive active commands to different banks is defined by t rrd. figure 10: activating a specific row in a specific bank figure 11: example: meeting t rcd ( t rrd) min when 2 < t rcd ( t rrd) min/ t ck 3 cs# we# cas# ras# cke a0?a12 ra ra = row address ba = bank address high ba0, ba1 ba ck ck# t command ba0, ba1 act act nop rrd t rcd ck ck# bank x bank y a0?a12 row row nop rd/wr nop bank y col nop t0 t1 t2 t3 t4 t5 t6 t7 don?t care nop
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 20 ?2003 micron technology, inc. reads read bursts are initiated with a read command, as shown in figure 12 on page 21. the starting column and bank addresses are pro- vided with the read command and auto precharge is either enabled or disabled for that burst access. if auto precharge is enabled, the row being accessed is pre- charged at the completion of the burst. note: for the read commands used in the follow- ing illustrations, auto precharge is disabled. during read bursts, the valid data-out element from the starting column address will be available fol- lowing the cas latency after the read command. each subsequent data-out element will be valid nomi- nally at the next positive or negative clock edge (i.e., at the next crossing of ck and ck#). figure 13 on page 22 shows general timing for each possible cas latency setting. dqs is driven by the ddr sdram along with output data. the initial low state on dqs is known as the read preamble; the low state coincident with the last data-out element is known as the read postamble. upon completion of a burst, assuming no other commands have been initiated, the dqs will go high- z. a detailed explanation of t dqsq (valid data-out skew), t qh (data-out window hold), and the valid data window are depicted in figure 40 on page 65 and figure 41 on page 66. a detailed explanation of t dqsck (dqs transition skew to ck) and t ac (data-out transition skew to ck) is depicted in figure 42 on page 67. data from any read burst may be concatenated with or truncated with data from a subsequent read command. in either case, a continuous flow of data can be maintained. the first data element from the new burst follows either the last element of a com- pleted burst or the last desired data element of a longer burst which is being truncated. the new read com- mand should be issued x cycles after the first read command, where x equals the number of desired data element pairs (pairs are required by the 2 n -prefetch architecture). this is shown in figure 14 on page 23. a read command can be initiated on any clock cycle following a previous read command. nonconsecutive read data is illustrated in figure 15, nonconsecutive read bursts, on page 24. full-speed random read accesses within a page (or pages) can be performed as shown in figure 16, rand om read accesses, on page 25. data from any read burst may be truncated with a burst terminate command, as shown in figure 17 on page 26. the burst terminate latency is equal to the read (cas) latency; i.e., the burst terminate command should be issued x cycles after the read command, where x equals the number of desired data element pairs (pairs are required by the 2 n -prefetch architecture). data from any read burst must be completed or truncated before a subsequent write command can be issued. if truncation is necessary, the burst ter- minate command must be used, as shown in figure 18 on page 27. the t dqss (nom) case is shown; the t dqss (max) case has a longer bus idle time. ( t dqss [min] and t dqss [max] are defined in the sec- tion on writes.) a read burst may be followed by, or truncated with, a precharge command to the same bank provided that auto precharge was not activated. the precharge command should be issued x cycles after the read command, where x equals the number of desired data element pairs (pairs are required by the 2 n -prefetch architecture). this is shown in figure 19 on page 28. following the pre- charge command, a subsequent command to the same bank cannot be issued until both t ras and t rp have been met. note that part of the row precharge time is hidden during the access of the last data ele- ments.
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 21 ?2003 micron technology, inc. figure 12: read command cs# we# cas# ras# cke ca x4: a0?a9, a11 x8: a0?a9 x16: a0?a8 a10 ba0,1 high en ap dis ap ba x4: a12 x8: a11, a12 x16: a9, a11, a12 ck ck# ca = column address ba = bank address en ap = enable auto precharge dis ap = disable auto precharge don?t care
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 22 ?2003 micron technology, inc. figure 13: read burst note: 1. do n = data-out from column n . 2. burst length = 4. 3. three subsequent elements of data-out ap pear in the programmed order following do n . 4. shown with nominal t ac, t dqsck, and t dqsq. ck ck# command read nop nop nop nop nop address bank a, col n read nop nop nop nop nop bank a , col n cl = 2 ck ck# command address dq dqs cl = 2.5 dq dqs do n do n t0 t1 t2 t3 t2n t3n t4 t5 t0 t1 t2 t3 t2n t3n t4 t5 don?t care transitioning data
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 23 ?2003 micron technology, inc. figure 14: consecutive read bursts note: 1. do n (or b ) = data-out from column n (or column b ). 2. burst length = 4 or 8 (if 4, the bursts are concatenated; if 8, the second burst interrupts the first). 3. three subsequent elements of data-out ap pear in the programmed order following do n. 4. three (or seven) subsequent elements of data-o ut appear in the programmed order following do b. 5. shown with nominal t ac, t dqsck, and t dqsq. 6. example applies only when read commands are issued to the same device. ck ck# command read nop read nop nop nop address bank, col n bank, col b command read nop read nop nop nop address bank, col n bank, col b cl = 2 ck ck# command address dq dqs cl = 2.5 dq dqs do n do b do n do b t0 t1 t2 t3 t2n t3n t4 t5 t4n t5n t0 t1 t2 t3 t2n t3n t4 t5 t4n t5n don?t care transitioning data
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 24 ?2003 micron technology, inc. figure 15: nonconsecutive read bursts note: 1. do n (or b ) = data-out from column n (or column b ). 2. burst length = 4 or 8 (if 4, the bursts are concatenated; if 8, the second burst interrupts the first). 3. three subsequent elements of data-out ap pear in the programmed order following do n . 4. three (or seven) subsequent elements of data-o ut appear in the programmed order following do b . 5. shown with nominal t ac, t dqsck, and t dqsq. ck ck# command read nop nop nop nop nop address bank, col n read bank, col b command address cl = 2 ck ck# command address dq dqs cl = 2.5 dq dqs do n t0 t1 t2 t3 t2n t3n t4 t5 t5n t6 read nop nop nop nop nop bank, col n read bank, col b t0 t1 t2 t3 t2n t3n t4 t5 t5n t6 do b do n do b don?t care transitioning data
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 25 ?2003 micron technology, inc. figure 16: random read accesses note: 1. do n (or x or b or g ) = data-out from column n (or column x or column b or column g ). 2. burst length = 2, 4 or 8 (if 4 or 8, the following burst interrupts the previous). 3. n ' or x ' or b ' or g ' indicates the next data-out following do n or do x or do b or do g , respectively . 4. reads are to an active row in any bank . 5. shown with nominal t ac, t dqsck, and t dqsq. ck ck# command read read read nop nop address bank, col n bank, col x bank, col b bank, col x bank, col b read bank, col g command address cl = 2 ck ck# command address dq dqs cl = 2.5 dq dqs do n do x' do g do n' do b do x do b' do n do x' do n' do b do x do b' t0 t1 t2 t3 t2n t3n t4 t5 t4n t5n read read read nop nop bank, col n read bank, col g t0 t1 t2 t3 t2n t3n t4 t5 t4n t5n don?t care transitioning data
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 26 ?2003 micron technology, inc. figure 17: terminating a read burst note: 1. do n = data-out from column n . 2. burst length = 4 or 8. 3. subsequent element of data-out appears in the programmed order following do n . 4. shown with nominal t ac, t dqsck, and t dqsq. 5. bst = burst terminate command; page remains open. ck ck# command read bst 5 nop nop nop nop address bank a , col n read bst 5 nop nop nop nop bank a , col n cl = 2 ck ck# command address dq dqs cl = 2.5 dq dqs do n do n t0 t1 t2 t3 t2n t4 t5 t0 t1 t2 t3 t2n t4 t5 don?t care transitioning data
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 27 ?2003 micron technology, inc. figure 18: read to write note: 1. do n = data-out from column n . 2. di b = data-in from column b . 3. burst length = 4 in the cases shown (applies for bursts of 8 as well; if the burst length is 2, the bst command shown can be nop). 4. one subsequent element of data-out appe ars in the programmed order following do n. 5. data-in elements are applied following di b in the programmed order . 6. shown with nominal t ac, t dqsck, and t dqsq. 7. bst = burst terminate command; 8. page remains open. ck ck# command read bst 7 nop nop nop address bank, col n write bank, col b t0 t1 t2 t3 t2n t4 t5 t4n t5n cl = 2 dq dqs dm t (nom) dqss di b ck ck# command read bst 7 nop write nop address bank a, col n nop t0 t1 t2 t3 t2n t4 t5 t5n cl = 2.5 dq dqs do n dm di b don?t care transitioning data do n t (nom) dqss
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 28 ?2003 micron technology, inc. figure 19: read to precharge note: 1. do n = data-out from column n . 2. burst length = 4, or an interrupted burst of 8. 3. three subsequent elements of data-out ap pear in the programmed order following do n . 4. shown with nominal t ac, t dqsck, and t dqsq. 5. read to precharge equals two clocks, which allows two data pairs of data-out. 6. a read command with auto-precharge enabled, provided t ras (min) is met, would cause a precharge to be per- formed at x number of clock cycles after the read command, where x = bl / 2. 7. an active command to the same bank is only allowed if t rc (min) has been satisfied. 8. pre = precharge command; act = active command. ck ck# command 6 read nop pre nop nop act address bank a , col n bank a , ( a or all ) bank a , row read nop pre nop nop act bank a , col n cl = 2 t rp t rp ck ck# command 6 address dq dqs cl = 2.5 dq dqs do n do n t0 t1 t2 t3 t2n t3n t4 t5 t0 t1 t2 t3 t2n t3n t4 t5 bank a , ( a or all ) bank a , row don?t care transitioning data
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 29 ?2003 micron technology, inc. writes write bursts are initiated with a write command, as shown in figure 20. the starting column and bank addresses are pro- vided with the write command, and auto precharge is either enabled or disabled for that access. if auto precharge is enabled, the row being accessed is pre- charged at the completion of the burst and after the t wr time. note: for the write commands used in the follow- ing illustrations, auto precharge is disabled. during write bursts, the first valid data-in element will be registered on the first rising edge of dqs follow- ing the write command, and subsequent data ele- ments will be registered on successive edges of dqs. the low state on dqs between the write command and the first rising edge is known as the write pream- ble; the low state on dqs following the last data-in element is known as the write postamble. the time between the write command and the first corresponding rising edge of dqs ( t dqss) is specified with a relatively wide range (from 75 per- cent to 125 percent of on e clock cycle). all of the write diagrams show the nominal case, and where the two extreme cases (i.e., t dqss [min] an d t dqss [max]) might not be intuitive, they have also been included. figure 21 on page 30 shows the nominal case and the extremes of t dqss for a burst of 4. upon completion of a burst, assuming no other commands have been initiated, the dq will remain high-z and any additional input data will be ignored. data for any write burst may be concatenated with or truncated with a subsequent write com- mand. in either case, a continuous flow of input data can be maintained. the new write command can be issued on any positive edge of clock following the pre- vious write command. the first data element from the new burst is applied after either the last element of a completed burst or the last desired data element of a longer burst which is being truncated. the new write command should be issued x cycles after the first write command, where x equals the number of desired data element pairs (pairs are required by the 2 n -prefetch architecture). figure 22 on page 31 shows concatenated bursts of 4. an example of nonconsecutive writes is shown in figure 23 on page 32. full-speed random write accesses within a page or pages can be performed as shown in figure 24 on page 33. figure 20: write command data for any write burst may be followed by a sub- sequent read command. to follow a write without truncating the write burst, t wtr should be met as shown in figure 25 on page 34. data for any write burst may be truncated by a subsequent read command, as shown in figure 26 on page 35. note that only the data-in pairs that are registered prior to the t wtr period are written to the internal array, and any subsequent data-in should be masked with dm, as shown in figure 27 on page 36. data for any write burst may be followed by a sub- sequent precharge command. to follow a write without truncating the write burst, t wr should be met as shown in figure 28 on page 37. data for any write burst may be truncated by a subsequent precharge command, as shown in figure 29 on page 38 and figure 30 on page 39. note that only the data-in pairs that are registered prior to the t wr period are written to the internal array, and any subsequent data-in should be masked with dm as shown in figures 29 and 30. after the precharge command, a subsequent command to the same bank cannot be issued until t rp is met. cs# we# cas# ras# cke ca a10 ba0, 1 high en ap dis ap ba ck ck# ca = column address ba = bank address en ap = enable auto precharge dis ap = disable auto precharge don?t care x4: a0?a9, a11 x8: a0?a9 x16: a0?a8 x4: a12 x8: a11, a12 x16: a9, a11, a12
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 30 ?2003 micron technology, inc. figure 21: write burst note: 1. di b = data-in for column b . 2. three subsequent elements of data-in are a pplied in the programmed order following di b . 3. an uninterrupted burst of 4 is shown. 4. a10 is low with the write command (auto precharge is disabled). dqs t dqss (max) t dqss (nom) t dqss (min) t dqss dm dq ck ck# command write nop nop address bank a , col b nop t0 t1 t2 t3 t2n dqs t dqss dm dq dqs t dqss dm dq di b di b di b don?t care transitioning data
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 31 ?2003 micron technology, inc. figure 22: consecutive write to write note: 1. di b , etc., = data-in for column b , etc. 2. three subsequent elements of data-in are a pplied in the programmed order following di b . 3. three subsequent elements of data-in are a pplied in the programmed order following di n . 4. an uninterrupted burst of 4 is shown . 5. each write command may be to any bank. ck ck# command write nop write nop nop address bank, col b nop bank, col n t0 t1 t2 t3 t2n t4 t5 t4n t3n t1n dq dqs dm di n di b don?t care transitioning data t dqss t dqss (nom)
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 32 ?2003 micron technology, inc. figure 23: nonconsecutive write to write note: 1. di b , etc., = data-in for column b , etc. 2. three subsequent elements of data-in are a pplied in the programmed order following di b . 3. three subsequent elements of data-in are a pplied in the programmed order following di n . 4. an uninterrupted burst of 4 is shown . 5. each write command may be to any bank. ck ck# command write nop nop nop nop address bank, col b write bank, col n t0 t1 t2 t3 t2n t4 t5 t4n t1n t5n dq dqs dm di n di b t dqss (nom) t dqss don?t care transitioning data
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 33 ?2003 micron technology, inc. figure 24: random write cycles note: 1. di b , etc., = data-in for column b , etc. 2. b' , etc., = the next data-in following di b , etc., according to the programmed burst order. 3. programmed burst length = 2, 4, or 8 in cases shown. 4. each write command may be to any bank. t dqss (nom) ck ck# command write write write write nop address bank, col b bank, col x bank, col n bank, col g write bank, col a t0 t1 t2 t3 t2n t4 t5 t4n t1n t3n t5n dq dqs dm di b di b' di x di x' di n di n' di a di a' di g di g' don?t care transitioning data
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 34 ?2003 micron technology, inc. figure 25: write to read - uninterrupting note: 1. di b = data-in for column b; do n = data-out for column n . 2. three subsequent elements of data-in are a pplied in the programmed order following di b . 3. an uninterrupted burst of 4 is shown. 4. t wtr is referenced from the first positive ck edge after the last data-in pair. 5. the read and write commands are to the same device. however, the read and write commands may be directed to different devices, in which case, t wtr is not required and the read command could be applied earlier. 6. a10 is low with the write command (auto precharge is disabled). t dqss (nom) ck ck# command write nop nop read nop nop address bank a , col b bank a , col n nop t0 t1 t2 t3 t2n t4 t5 t1n t6 t6n t wtr cl = 2 dq dqs dm di b do n t dqss t dqss (min) cl = 2 dq dqs dm di b do n t dqss t dqss (max) cl = 2 dq dqs dm di b do n t dqss don?t care transitioning data
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 35 ?2003 micron technology, inc. figure 26: write to read ? interrupting note: 1. di b = data-in for column ;, do n = data-out for column n . 2. an interrupted burst of 4 is shown; two data elements are written. 3. one subsequent element of data-in is a pplied in the programmed order following di b . 4. t wtr is referenced from the first positive ck edge after the last data-in pair. 5. a10 is low with the write command (auto precharge is disabled). 6. dqs is required at t2 and t2n (nominal case) to register dm. 7. if the burst of 8 was used, dm and dqs would be required at t3 and t3n because the read command would not mask these two data elements. t dqss (nom) ck ck# command write nop nop nop nop nop address bank a , col b bank a , col n read t0 t1 t2 t3 t2n t4 t5 t5n t1n t6 t6n t wtr cl = 2 dq dqs dm di b do n t dqss (min) cl = 2 dq dqs dm di b t dqss (max) cl = 2 dq dqs dm di b do n do n don?t care transitioning data t dqss t dqss t dqss t3n
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 36 ?2003 micron technology, inc. figure 27: write to read ? odd number of data, interrupting note: 1. di b = data-in for column b; do n = data-out for column n . 2. an interrupted burst of 4 is shown; one data element is written. 3. t wtr is referenced from the first positive ck edge after the last desired data-in pair (not the last two data elements). 4. a10 is low with the write command (auto precharge is disabled). 5. dqs is required at t1n, t2, and t2n (nominal case) to register dm. 6. if the burst of 8 was used, dm and dqs would be require d at t3?t3n because the read command would not mask these data elements. t dqss (nom) ck ck# command write nop nop nop nop nop address bank a , col b bank a , col n read t0 t1 t2 t3 t2n t4 t5 t1n t6 t6n t5n t wtr cl = 2 dq dqs dm di b do n t dqss (min) cl = 2 dq dqs dm di b do n t dqss (max) cl = 2 dq dqs dm di b do n don?t care transitioning data t dqss t dqss t dqss t3n
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 37 ?2003 micron technology, inc. figure 28: write to pr echarge - uninterrupting note: 1. di b = data-in for column b . 2. three subsequent elements of data-in are a pplied in the programmed order following di b . 3. an uninterrupted burst of 4 is shown. 4. t wr is referenced from the first positive ck edge after the last data-in pair. 5. the precharge and write commands are to the same device. however, the precharge and write commands may be to different devices, in which case, t wr is not required and the precharge command could be applied earlier. 6. a10 is low with the write command (auto precharge is disabled). 7. pre = precharge command. t dqss (nom) ck ck# command write nop nop nop pre 7 nop address bank a , col b bank, ( a or all ) nop t0 t1 t2 t3 t2n t4 t5 t1n t6 t wr t rp dq dqs dm di b t dqss (min) dq dqs dm di b t dqss (max) dq dqs dm di b don?t care transitioning data t dqss t dqss t dqss
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 38 ?2003 micron technology, inc. figure 29: write to precharge ? interrupting note: 1. di b = data-in for column b . 2. subsequent element of data-in is appl ied in the programmed order following di b . 3. an interrupted burst of 8 is shown; two data elements are written. 4. t wr is referenced from the first positive ck edge after the last data-in pair. 5. a10 is low with the write command (auto precharge is disabled). 6. dqs is required at t4 and t4n (nominal case) to register dm. 7. if the burst of 4 was used, dqs and dm would not be required at t3, t3n, t4, and t4n. 8. pre = precharge command. t dqss t dqss (nom) ck ck# command write nop nop pre 8 nop nop address bank a , col b bank, ( a or all ) nop t0 t1 t2 t3 t2n t4 t5 t1n t6 t wr t rp dq dqs dm di b t dqss t dqss (min) dq dqs dm di b t dqss t dqss (max) dq dqs dm di b don?t care transitioning data t3n t4n
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 39 ?2003 micron technology, inc. figure 30: write to precharge ? odd number of data ? interrupting note: 1. di b = data-in for column b . 2. an interrupted burst of 8 is shown; one data element is written. 3. t wr is referenced from the first positive ck edge after the last data-in pair. 4. a10 is low with the write command (auto precharge is disabled). 5. dqs is required at t4 and t4n (nominal case) to register dm. 6. if the burst of 4 was used, dqs and dm would not be required at t3, t3n, t4, and t4n. 7. pre = precharge command. t dqss t dqss (nom) ck ck# command write nop nop pre 7 nop nop address bank a , col b bank, ( a or all ) nop t0 t1 t2 t3 t2n t4 t5 t1n t6 t wr t rp dq dqs dm di b t dqss t dqss (min) dq dqs dm t dqss t dqss (max) dq dqs dm di b di b don?t care transitioning data t3n t4n
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 40 ?2003 micron technology, inc. precharge the precharge command, as shown in figure 31, is used to deactivate the open row in a particular bank or the open row in all banks. the bank(s) will be avail- able for a subsequent row access some specified time ( t rp) after the precharge command is issued. input a10 determines whether one or all banks are to be pre- charged, and in the case where only one bank is to be precharged, inputs ba0, ba1 select the bank. when all banks are to be precharged, inputs ba0, ba1 are treated as ?don?t care.? once a bank has been pre- charged, it is in the idle state and must be activated prior to any read or write commands being issued to that bank. figure 31: precharge command power-down (cke not active) unlike sdr sdrams, ddr sdrams require cke to be active at all times that an access is in progress, from the issuing of a read or write command until com- pletion of the access. thus, a clock suspend is not sup- ported. for reads, an access completion is defined when the read postamble is satisfied; for writes, an access completion is defined when the write recovery time ( t wr) is satisfied. power-down, shown in figure 32, power-down, on page 41, is entered when cke is registered low and all of the criteria listed in table 8, on page 41, are met. if power-down occurs when all banks are idle, this mode is referred to as precharge power-down; if power-down occurs when there is a row active in any bank, this mode is referred to as active power-down. entering power-down deactivates the input and output buffers, excluding ck, ck#, and cke. for maximum power sav- ings, the dll is frozen during precharge power-down mode. exiting power-down requires the device to be at the same voltage and frequency as when it entered power-down. however, power-down duration is lim- ited by the refresh requirements of the device ( t refc). while in power-down, cke low and a stable clock signal must be maintained at the inputs of the ddr sdram, while all other input signals are ?don?t care.? the power-down state is synchronously exited when cke is registered high (in conjunction with a nop or deselect command). a valid executable command may be applied one clock cycle later. cs# we# cas# ras# cke a10 ba0,1 high all banks one bank ba a0?a9, a11, a12 ck ck# ba = bank address (if a10 is low; otherwise ?don?t care?) don?t care
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 41 ?2003 micron technology, inc. figure 32: power-down note: 1. cke n is the logic state of cke at clock edge n ; cke n-1 was the state of cke at the previous clock edge. 2. current state is the state of the ddr sdram immediately prior to clock edge n . 3. command n is the command registered at clock edge n , and action n is a result of command n . 4. all states and sequences not shown are illegal or reserved. 5. cke must not drop low during a column access. for a read, this means cke must stay high until after the read postam- ble time; for a write, cke must stay high until the write recovery time ( t wr) has been met. 6. once initialized, including during self refresh mode, v ref must be powered within the specified range. 7. upon exit of the self refresh mode, the dll is automatica lly enabled, but a dll reset must still occur. a minimum of 200 clock cycles is needed before applying a read command for the dll to lock. deselect or nop commands should be issued on any clock edges occurring during the t xsnr period. t is t is no read/write access in progress exit power-down mode enter power-down mode cke ck ck# command nop ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) nop valid t0 t1 t2 ta0 ta1 ta2 valid don?t care valid table 8: truth table ? cke notes: 1?6 cke n-1 cke n current state command n action n notes llpower-down x maintain power-down self refresh x maintain self refresh l h power-down deselect or nop exit power-down self refresh deselect or nop exit self refresh 7 h l all banks idle deselect or nop precharge power-down entry bank(s) active deselect or nop active power-down entry all banks idle auto refresh self refresh entry h h see table 9 on page 42
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 42 ?2003 micron technology, inc. note: 1. this table applies when cke n-1 was high and cke n is high (see table 8 on page 41) and after t xsnr has been met (if the previous state was self refresh). 2. this table is bank-specific, except where noted (i.e., the cu rrent state is for a specific bank and the commands shown are those allowed to be issued to that bank when in th at state). exceptions are covered in the notes below. 3. current state definitions: idle: the bank has been precharged, and t rp has been met. row active: a row in the bank has been activated, and t rcd has been met. no data bursts/accesses and no register accesses are in progress. read: a read burst has been initiated, with auto precharge disabled, and has not yet terminated or been termi- nated. write: a write burst has been initiated, with auto precharge disabled, and has not yet terminated or been ter- minated. 4. the following states must not be interrupted by a command issued to the same bank. command inhibit or nop com- mands, or allowable commands to the other bank should be issued on any clock edge occurring during these states. allowable commands to the other bank are determined by i ts current state and table 9, truth table ? current state bank n ? command to bank n, on page 42 and according to table 10, truth table ? current state bank n? command to bank m, on page 44. precharging: starts with registration of a precharge command and ends when t rp is met. once t rp is met, the bank will be in the idle state. row activating: starts with registration of an active command and ends when t rcd is met. once t rcd is met, the bank will be in the ?row active? state. read w/auto-precharge enabled: starts with registration of a read command with auto precharge enabled and ends when t rp has been- met. once t rp is met, the bank will be in the idle state. write w/auto- precharge enabled: starts with registration of a write command with auto precharge enabled and ends when t rp has been met. once t rp is met, the bank will be in the idle state. table 9: truth table ? current state bank n ? command to bank n notes: 1?6; notes appear below and on next page current state cs# ras# cas# we# command/action notes any h x x x deselect (nop/continue previous operation) lhh h no operation (nop/continue previous operation) idle l l h h active (select and activate row) ll l h auto refresh 7 ll l l load mode register 7 row active l h l h read (select column and start read burst) 10 lh l l write (select column and start write burst) 10 llh l precharge (deactivate row in bank or banks) 8 read (auto- precharge disabled) lh l h read (select column and start new read burst) 10 lh l l write (select column and start write burst) 10, 12 llh l precharge (truncate read burst, start precharge) 8 lhh l burst terminate 9 write (auto- precharge disabled) lh l h read (select column and start read burst) 10, 11 lh l l write (select column and start new write burst) 10 llh l precharge (truncate write burst, start precharge) 8, 11
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 43 ?2003 micron technology, inc. 5. the following states must not be interrupted by any ex ecutable command; command inhibit or nop commands must be applied on each positive clock edge during these states. refreshing: starts with registration of an auto refresh command and ends when t rfc is met. once t rfc is met, the ddr sdram will be in the all banks idle state. accessing mode register: starts with registration of a load mode register command and ends when t mrd has been met. once t mrd is met, the ddr sdram will be in the all banks idle state. precharging all: starts with registration of a precharge all command and ends when t rp is met. once t rp is met, all banks will be in the idle state. 6. all states and sequences not shown are illegal or reserved. 7. not bank-specific; requires that all banks are idle and bursts are not in progress. 8. may or may not be bank-specific; if multiple banks are to be precharged, each must be in a valid state for precharging. 9. not bank-specific; burst terminate affects the most recent read burst, regardless of bank. 10.reads or writes listed in the command/action column include reads or writes with auto precharge enabled and reads or writes with auto precharge disabled. 11.requires appropriate dm masking. 12.a write command may be applied after the completion of the read burst; otherwise, a burst terminate must be used to end the read burst prior to asserting a write command.
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 44 ?2003 micron technology, inc. note: 1. this table applies when cke n-1 was high and cke n is high (see truth table 2) and after t xsnr has been met (if the previ- ous state was self refresh). 2. this table describes alternate bank operation except where noted (i.e., the current state is for bank n and the commands shown are those allowed to be issued to bank m , assuming that bank m is in such a state that the given command is allowable). exceptions are covered in the notes below. 3. current state definitions: idle: the bank has been precharged, and t rp has been met. row active: a row in the bank has been activated, and t rcd has been met. no data bursts/accesses and no register accesses are in progress. read: a read burst has been initiated, with auto precharge disabled, and has not yet terminated or been termi- nated. write: a write burst has been initiated, with auto precharge disabled, and has not yet terminated or been ter- minated read with auto precharge enabled: see following text ? 3a write with auto precharge enabled: see following text ? 3a a. the read with auto precharge enabled or write with auto precharge enabled states can each be broken into two parts: the access period and the precharge period. for read with auto precharge, the precharge period is defined as if the same burst was executed with auto precharge disabled and then followed with the earliest possible precharge command that still accesses all of the data in the burst. for write with auto precharge, the precharge period begins when t wr ends, with t wr measured as if auto precharge was disabled. the access period starts with registration of the command and ends where the precharge period (or t rp) begins. table 10: truth table ? current state bank n ? command to bank m notes: 1?6; notes appear below and on next page current state cs# ras# cas# we# command/action notes any hx x x deselect (nop/continue previous operation) lhh h no operation (nop/continue previous operation) idle xx x x any command otherwise allowed to bank m row activating, active, or precharging llhh active (select and activate row) lh l h read (select column and start read burst) 7 lh l l write (select column and start write burst) 7 llh l precharge read (auto-precharge disabled) llhh active (select and activate row) lh l h read (select column and start new read burst) 7 lh l l write (select column and start write burst) 7, 9 llh l precharge write (auto- precharge disabled) llhh active (select and activate row) lh l h read (select column and start read burst) 7, 8 lh l l write (select column and start new write burst) 7 llh l precharge read (with auto- precharge) llhh active (select and activate row) lh l h read (select column and start new read burst) 7, 3a lh l l write (select column and start write burst) 7, 9, 3a llh l precharge write (with auto- precharge) llhh active (select and activate row) lh l h read (select column and start read burst) 7, 3a lh l l write (select column and start new write burst) 7, 3a llh l precharge
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 45 ?2003 micron technology, inc. this device supports concurrent auto pr echarge such that when a read with auto precharge is enabled or a write with auto precharge is enabled any command to other banks is allowed, as long as that command does not interrupt the read or write data transfer already in process. in either case, all other related limitations apply (e.g., contention between read data and write data must be avoided). b. the minimum delay from a read or write command with auto precharge enabled, to a command to a different bank, is summarized below. note: cl ru = cas latency (cl) rounded up to the next integer bl = bust length 4. auto refresh and load mode register commands may only be issued when all banks are idle. 5. a burst terminate command cannot be issued to another bank ; it applies to the bank represented by the current state only. 6. all states and sequences not shown are illegal or reserved. 7. reads or writes listed in the command/action column include reads or writes with auto precharge enabled and reads or writes with auto precharge disabled. 8. requires appropriate dm masking. 9. a write command may be applied after the completion of the read burst; otherwise, a burst terminate must be used to end the read burst prior to asserting a write command. from command to c o m m a n d minimum delay (with concurrent auto precharge) write w/ap read or read w/ap [1 + (bl/2)] * t ck + t wtr write or write w/ap (bl/2) * t ck precharge 1 t ck active 1 t ck read w/ap read or read w/ap (bl/2) * t ck write or write w/ap [cl ru + (bl/2)] * t ck precharge 1 t ck active 1 t ck
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 46 ?2003 micron technology, inc. absolute maximum ratings stresses greater than those listed may cause perma- nent damage to the device. this is a stress rating only, and functional operation of the device at these or any other conditions above those indicated in the opera- tional sections of this specification is not implied. exposure to absolute maximum rating conditions for extended periods may affect reliability. v dd supply voltage relative to vss ...................................... -1v to +3.6v v dd q supply voltage relative to v ss ..................................... -1v to +3.6v v ref and inputs voltage relative to v ss ..................................... -1v to +3.6v i/o pins voltage relative to v ss ....................... -0.5v to v dd q +0.5v operating temperature, t a (ambient, commercial) ..................... 0c to +70c operating temperature, t a (ambient, industrial).......................-40c to +85c storage temperature (plastic) ...............-55c to +150c power dissipation........................................................ 1w short circuit output current .................................50ma table 11: dc electrical characteristics and operating conditions 0c t a +70c; v dd q = +2.5v 0.2v, v dd = +2.5v 0.2v notes: 1?5, 16; notes appear on pages 59?62 parameter/condition symbol min max units notes supply voltage v dd 2.3 2.7 v 36, 41, 46 i/o supply voltage v dd q 2.3 2.7 v 36, 41, 44,46 i/o reference voltage v ref 0.49 x v dd q0.51 x v dd qv 6, 44 i/o termination voltage (system) v tt v ref - 0.04 v ref + 0.04 v7, 44 input high (logic 1) voltage v ih ( dc )v ref + 0.15 v dd + 0.3 v28 input low (logic 0) voltage v il ( dc ) -0.3 v ref - 0.15 v28 input leakage current any input 0v v in v dd , v ref pin 0v vin 1.35v (all other pins not under test = 0v) i i -2 2 a output leakage current (dqs are disabled; 0v vout v dd q ) i oz -5 5 a output levels: full drive option - x4, x8, x16 high current (v out = v dd q - 0.373v, minimum v ref , minimum v tt ) i oh -16.8 - ma 37, 39 low current (v out = 0.373v, maximum v ref , maximum v tt ) i ol 16.8 - ma output levels: reduced drive option - x16 only high current (v out = v dd q - 0.763v, minimum v ref , minimum v tt ) i ohr -9 - ma 38, 39 low current (v out = 0.763v, maximum v ref , maximum v tt ) i olr 9-ma table 12: ac input operating conditions 0c t a +70c; v dd q = +2.5v 0.2v, v dd = +2.5v 0.2v notes: 1?5, 14, 16; notes appear on pages 59?62 parameter/condition symbol min max units notes input high (logic 1) voltage v ih ( ac )v ref + 0.310 - v 14, 28, 40 input low (logic 0) voltage v il ( ac ) - v ref - 0.310 v 14, 28, 40 i/o reference voltage v ref ( ac ) 0.49 x v dd q 0.51 x v dd q v6
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 47 ?2003 micron technology, inc. figure 33: input voltage waveform 0.940v 1.100v 1.200v 1.225v 1.250v 1.275v 1.300v 1.400v 1.560v v il ac v il dc v ref -ac noise v ref -dc error v ref +dc error v ref +ac noise receiver transmitter v ih dc v ih ac v oh (min) (1.670v 1 for sstl_2 termination) v in ac - provides margin between v ol (max) and v il ac v ss q v dd q (2.3v minimum) v ol (max) (0.83v 2 for sstl_2 termination) system noise margin (power/ground, crosstalk, signal integrity attenuation) note: 1. v oh (min) with test load is 1.927v 2. v ol (max) with test load is 0.373v 3. numbers in diagram reflect nomimal values utilizing circuit below. reference point 25 ? 25 ? v tt
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 48 ?2003 micron technology, inc. figure 34: sstl_2 clock input note: 1. this provides a minimum of 1.15v to a maximum of 1.35v and is always half of v dd q. 2. ck and ck# must cross in this region. 3. ck and ck# must meet at least v id (dc) min when static and is centered around v mp (dc) 4. ck and ck# must have a minimum 700mv peak-to-peak swing. 5. ck or ck# may not be more positive than v dd q + 0.3v or more negative than vss - 0.3v. 6. for ac operation, all dc clock requirements must also be satisfied. 7. numbers in diagram reflect nominal values. table 13: clock input operating conditions 0c t a +70c; v dd q = +2.5v 0.2v, v dd = +2.5v 0.2v notes: 1?5, 15, 16, 30; notes appear on pages 59?62 parameter/condition symbol min max units notes clock input midpoint voltage; ck and ck# v mp ( dc ) 1.15 1.35 v 6, 9 clock input voltage level; ck and ck# v in ( dc ) -0.3 v dd q + 0.3 v6 clock input differential voltage; ck and ck# v id ( dc ) 0.36 v dd q + 0.6 v6, 8 clock input differential voltage; ck and ck# v id ( ac ) 0.7 v dd q + 0.6 v8 clock input crossing point voltage; ck and ck# v ix ( ac ) 0.5 x v dd q - 0.2 0.5 x v dd q + 0.2 v9 ck ck# 2.80v 2 3 5 5 maximum clock level minimum clock level 4 - 0.30v 1.25v 1.45v 1.05v v id (ac) v id (dc) x 1 v mp (dc) v ix (ac) x
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 49 ?2003 micron technology, inc. table 14: capacitance (x4, x8 tsop) note: 13; notes appear on pages 59?62 parameter symbol min max units notes delta input/output capacitance: dq0?dq3 (x4), dq0?dq7 (x8) dc io ?0.50pf 24 delta input capacitance: command and address dc i 1 ?0.50pf 29 delta input capacitance: ck, ck# dc i 2 ?0.25pf 29 input/output capacitance: dqs, dqs, dm c io 4.0 5.0 pf input capacitance: command and address c i 1 2.0 3.0 pf input capacitance: ck, ck# c i 2 2.0 3.0 pf input capacitance: cke c i 3 2.0 3.0 pf table 15: capacitance (x4, x8 fbga) note: 13; notes appear on pages 59?62 parameter symbol min max units notes delta input/output capacitance: dqs, dqs, dm dc io ?0.50pf 24 delta input capacitance: command and address dc i 1 ?0.50pf 29 delta input capacitance: ck, ck# dc i 2 ?0.25pf 29 input/output capacitance: dqs, dqs, dm c io 3.5 4.5 pf input capacitance: command and address c i 1 1.5 2.5 pf input capacitance: ck, ck# c i 2 1.5 2.5 pf input capacitance: cke c i 3 1.5 2.5 pf
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 50 ?2003 micron technology, inc. table 16: capacitance (x16 tsop) note: 13; notes appear on pages 59?62 parameter symbol min max units notes delta input/output capacitance: dq0?dq7, ldqs, ldm dc iol ?0.50pf 24 delta input/output capacitance: dq8?dq15, udqs, udm dc iou ?0.50pf 24 delta input capacitance: command and address dc i 1 ?0.50pf 29 delta input capacitance: ck, ck# dc i 2 ?0.25pf 29 input/output capacitance: dq, ldqs, udqs, ldm, udm c io 4.0 5.0 pf input capacitance: command and address c i 1 2.0 3.0 pf input capacitance: ck, ck# c i 2 2.0 3.0 pf input capacitance: cke c i 3 2.0 3.0 pf table 17: capacitance (x16 fbga) note: 13; notes appear onpages 59?62 parameter symbol min max units notes delta input/output capacitance: dq0?dq7, ldqs, ldm dc iol ?0.50pf 24 delta input/output capacitance: dq8?dq15, udqs, udm dc iou ?0.50pf 24 delta input capacitance: command and address dc i 1 ?0.50pf 29 delta input capacitance: ck, ck# dc i 2 ?0.25pf 29 input/output capacitance: dq, ldqs, udqs, ldm, udm c io 3.5 4.5 pf input capacitance: command and address c i 1 1.5 2.5 pf input capacitance: ck, ck# c i 2 1.5 2.5 pf input capacitance: cke c i 3 1.5 2.5 pf
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 51 ?2003 micron technology, inc. ta bl e 1 8 : i dd specifications and conditions (x4, x8; -6/-6r/-6t/-75e) 0c t a +70c; v dd q = +2.5v 0.2v, v dd = +2.5v 0.2v notes: 1?5, 10, 12, 14, 47; notes appear on pages 59?62; see also table 22, i dd test cycle times, on page 55 max parameter/condition symbol -6r -6/6t -75e units notes operating current: one bank; active precharge; t rc = t rc (min); t ck = t ck (min); dq, dm, and dqs inputs changing once per clock cycle; address and control inputs changing once every two clock cycles i dd 0 155 125 125 ma 22, 48 operating current: one bank; active-read precharge; burst = 4; t rc = t rc (min); t ck = t ck (min); i out = 0ma; address and control inputs changing once per clock cycle i dd 1 210 170 160 ma 22, 48 precharge power-down standby current: all banks idle; power-down mode; t ck = t ck (min); cke = (low) i dd 2p 5 4 4 ma 23, 32, 50 idle standby current: cs# = high; all banks are idle; t ck = t ck (min); cke = high; address and other control inputs changing once per clock cycle; v in = v ref for dq, dqs, and dm i dd 2f 50 50 45 ma 51 active power-down standby current: one bank active; power-down mode; t ck = t ck (min); cke = low i dd 3p 40 30 25 ma 23, 32, 50 active standby current: cs# = high; cke = high; one bank active ; t rc = t ras (max); t ck = t ck (min); dq, dm, and dqs inputs changing twice per clock cycle; address and other control inputs changing once per clock cycle i dd 3n 60 60 50 ma 22 operating current: burst = 2; reads; continuous burst; one bank active; address and control inputs changing once per clock cycle; t ck = t ck (min); i out = 0ma i dd 4r 215 175 150 ma 22, 48 operating current: burst = 2; writes; continuous burst; one bank active; address and control inputs changing once per clock cycle; t ck = t ck (min); dq, dm, and dqs inputs changing twice per clock cycle i dd 4w 235 155 135 ma 22 auto refresh burst current: t rc = t refc (min) i dd 5 264 255 235 ma 50 t refc = 7.8s i dd 5a 6 6 6 ma 27, 50 self refresh current: cke 0.2v standard i dd 6 544ma 11 low power (l) i dd 6a n/a 2 2 ma 11 operating current: four-bank interleaving reads (burst = 4) with auto precharge, t rc = minimum t rc allowed; t ck = t ck (min); address and control inputs change only during active read or write commands i dd 7 470 405 350 ma 22, 49
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 52 ?2003 micron technology, inc. ta bl e 1 9 : i dd specifications and conditions (x4, x8; -75z/-75) 0c t a +70c; v dd q = +2.5v 0.2v, v dd = +2.5v 0.2v notes: 1?5, 10, 12, 14, 47; notes appear on pages 59?62; see also table 22, i dd test cycle times, on page 55 max parameter/condition symbol -75z -75 units notes operating current: one bank; active precharge; t rc = t rc (min); t ck = t ck (min); dq, dm, and dqs inputs changing once per clock cycle; address and control inputs changing once every two clock cycles i dd 0 105 120 ma 22, 48 operating current: one bank; active-read precharge; burst = 4; t rc = t rc (min); t ck = t ck (min); i out = 0ma; address and control inputs changing once per clock cycle i dd 1 145 155 ma 22, 48 precharge power-down standby current: all banks idle; power-down mode; t ck = t ck (min); cke = (low) i dd 2p 4 4 ma 23, 32, 50 idle standby current: cs# = high; all banks are idle; t ck = t ck (min); cke = high; address and other control inputs changing once per clock cycle; v in = v ref for dq, dqs, and dm i dd 2f 45 45 ma 51 active power-down standby current: one bank active; power-down mode; t ck = t ck (min); cke = low i dd 3p 25 30 ma 23, 32, 50 active standby current: cs# = high; cke = high; one bank active ; t rc = t ras (max); t ck = t ck (min); dq, dm, and dqs inputs changing twice per clock cycle; address and other control inputs changing once per clock cycle i dd 3n 50 50 ma 22 operating current: burst = 2; reads; continuous burst; one bank active; address and control inputs changing once per clock cycle; t ck = t ck (min); i out = 0ma i dd 4r 150 175 ma 22, 48 operating current: burst = 2; writes; continuous burst; one bank active; address and control inputs changing once per clock cycle; t ck = t ck (min); dq, dm, and dqs inputs changing twice per clock cycle i dd 4w 135 190 ma 22 auto refresh burst current: t rc = t refc(min) i dd 5 235 245 ma 50 t refc = 7.8s i dd 5a 6 6 ma 27, 50 self refresh current: cke 0.2v standard i dd 6 44 ma 11 low power (l) i dd 6a 22 ma 11 operating current: four-bank interleaving reads (burst = 4) with auto precharge, t rc = minimum t rc allowed; t ck = t ck (min); address and control inputs change only during active read or write commands i dd 7 350 365 ma 22, 49
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 53 ?2003 micron technology, inc. ta bl e 2 0 : i dd specifications and conditions (x16; -6/-6r/-6t/-75e) 0c t a +70c; v dd q = +2.5v 0.2v, v dd = +2.5v 0.2v notes: 1?5, 10, 12, 14, 47; notes appear on pages 59?62; see also table 22, i dd test cycle times, on page 55 max parameter/condition symbol -6r -6/6t -75e units notes operating current: one bank; active precharge; t rc = t rc (min); t ck = t ck (min); dq, dm, and dqs inputs changing once per clock cycle; address and control inputs changing once every two clock cycles i dd 0 155 125 125 ma 22, 48 operating current: one bank; active-read precharge; burst = 4; t rc = t rc (min); t ck = t ck (min); i out = 0ma; address and control inputs changing once per clock cycle i dd 1 210 180 170 ma 22, 48 precharge power-down standby current: all banks idle; power-down mode; t ck = t ck (min); cke = (low) i dd 2p 5 4 4 ma 23, 32, 50 idle standby current: cs# = high; all banks are idle; t ck = t ck (min); cke = high; address and other control inputs changing once per clock cycle; v in = v ref for dq, dqs, and dm i dd 2f 50 50 45 ma 51 active power-down standby current: one bank active; power-down mode; t ck = t ck (min); cke = low i dd 3p 35 30 25 ma 23, 32, 50 active standby current: cs# = high; cke = high; one bank active ; t rc = t ras (max); t ck = t ck (min); dq, dm, and dqs inputs changing twice per clock cycle; address and other control inputs changing once per clock cycle i dd 3n 60 60 50 ma 22 operating current: burst = 2; reads; continuous burst; one bank active; address and control inputs changing once per clock cycle; t ck = t ck (min); i out = 0ma i dd 4r 225 220 185 ma 22, 48 operating current: burst = 2; writes; continuous burst; one bank active; address and control inputs changing once per clock cycle; t ck = t ck (min); dq, dm, and dqs inputs changing twice per clock cycle i dd 4w 250 165 145 ma 22 auto refresh burst current: t rc = t refc (min) i dd 5 265 255 235 ma 50 t refc = 7.8s i dd 5a 866ma27, 50 self refresh current: cke 0.2v standard i dd 6 544ma 11 low power (l) i dd 6a na 2 2 ma 11 operating current: four-bank interleaving reads (burst = 4) with auto precharge, t rc = minimum t rc allowed; t ck = t ck (min); address and control inputs change only during active read or write commands i dd 7 480 440 380 ma 22, 49
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 54 ?2003 micron technology, inc. ta bl e 2 1 : i dd specifications and conditions (x16; -75z/-75) 0c t a +70c; v dd q = +2.5v 0.2v, v dd = +2.5v 0.2v notes: 1?5, 10, 12, 14, 47; notes appear on pages 59?62; see also table 22, i dd test cycle times, on page 55 max parameter/condition symbol -75z -75 units notes operating current: one bank; active precharge; t rc = t rc (min); t ck = t ck (min); dq, dm, and dqs inputs changing once per clock cycle; address and control inputs changing once every two clock cycles i dd 0 105 120 ma 22, 48 operating current: one bank; active-read precharge; burst = 4; t rc = t rc (min); t ck = t ck (min); i out = 0ma; address and control inputs changing once per clock cycle i dd 1 155 165 ma 22, 48 precharge power-down standby current: all banks idle; power-down mode; t ck = t ck (min); cke = (low) i dd 2p 4 4 ma 23, 32, 50 idle standby current: cs# = high; all banks are idle; t ck = t ck (min); cke = high; address and other control inputs changing once per clock cycle; v in = v ref for dq, dqs, and dm i dd 2f 45 45 ma 51 active power-down standby current: one bank active; power-down mode; t ck = t ck (min); cke = low i dd 3p 25 30 ma 23, 32, 50 active standby current: cs# = high; cke = high; one bank active ; t rc = t ras (max); t ck = t ck (min); dq, dm, and dqs inputs changing twice per clock cycle; address and other control inputs changing once per clock cycle i dd 3n 50 50 ma 22 operating current: burst = 2; reads; continuous burst; one bank active; address and control inputs changing once per clock cycle; t ck = t ck (min); i out = 0ma i dd 4r 185 250 ma 22, 48 operating current: burst = 2; writes; continuous burst; one bank active; address and control inputs changing once per clock cycle; t ck = t ck (min); dq, dm, and dqs inputs changing twice per clock cycle i dd 4w 145 250 ma 22 auto refresh burst current: t rc = t refc (min) i dd 5 235 245 ma 50 t refc = 7.8s i dd 5a 6 6 ma 27, 50 self refresh current: cke 0.2v standard i dd 6 44ma 11 low power (l) i dd 6a 22ma 11 operating current: four-bank interleaving reads (burst = 4) with auto precharge, t rc = minimum t rc allowed; t ck = t ck (min); address and control inputs change only during active read or write commands i dd 7 380 400 ma 22, 49
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 55 ?2003 micron technology, inc. ta bl e 2 2 : i dd test cycle times values reflect number of clock cycles for each test. idd test speed grade clock cycle time t rrd t rcd t ras t rp t rc t rfc t refi cl i dd 0 -75/75z 7.5ns na na 6 3 9 na na na -75e 7.5ns na na 6 2 8 na na na -6/6t/6r 6ns na na 7 3 10 na na na i dd 1 -75 7.5ns na na 6 3 9 na na 2.5 -75z 7.5ns na na 6 3 9 na na 2 -75e 7.5ns na na 6 2 8 na na 2 -6/6t/6r 6ns na na 7 3 10 na na 2.5 i dd 4r -75 7.5ns na 3 na na na na na 2.5 -75z 7.5ns na 3 na na na na na 2 -75e 7.5ns na 2 na na na na na 2 -6/6t/6r 6ns na 3 na na na na na 2.5 i dd 4w -75 7.5ns na 3 na na na na na na -75z 7.5ns na 3 na na na na na na -75e 7.5ns na 2 na na na na na na -6/6t/6r 6ns na 3 na na na na na na i dd 5 -75/75z 7.5ns na na na 3 na 10 na na -75e 7.5ns na na na 2 na 9 na na -6/6t/6r 6ns na na na 3 na 12 na na i dd 5a -75/75z 7.5ns na na na 3 na na 1,030 na -75e 7.5ns na na na 2 na na 1,031 na -6/6t/6r 6ns na na na 3 na na 1,288 na i dd 7 -75 7.5ns 2/4 3 na 3 10 na na 2.5 -75z 7.5ns 2/4 3 na 3 10 na na 2 -75e 7.5ns 2 3 na 2 8 na na 2 -6/6t/6r 6ns 2/4 3 na 3 10 na na 2.5
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 56 ?2003 micron technology, inc. table 23: electrical characteristics and recommended ac operating conditions (-6/-6t/-6r/-75e) notes: 1?5, 14?17, 33, 46; notes appear on pages 59?62; 0c t a +70c; v dd q = +2.5v 0.2v, v dd = +2.5v 0.2v ac characteristics -6 (fbga) -6t/6r (tsop) -75e parameter symbol min max min max min max units notes access window of dqs from ck/ck# t ac -0.70 +0.70 -0.70 +0.70 -0.75 +0.75 ns ck high-level width t ch 0.45 0.55 0.45 0.55 0.45 0.55 t ck 30 ck low-level width t cl 0.45 0.55 0.45 0.55 0.45 0.55 t ck 30 clock cycle time cl = 2.5 t ck (2.5) 6 13 6 13 7.5 13 ns 45, 52 cl = 2 t ck (2) 7.5 13 7.5 13 7.5 13 ns 45, 52 dq and dm input hold time relative to dqs t dh 0.45 0.45 0.5 ns 26, 31 dq and dm input setup time relative to dqs t ds 0.45 0.45 0.5 ns 26, 31 dq and dm input pulse width (for each input) t dipw 1.75 1.75 1.75 ns 31 access window of dqs from ck/ck# t dqsck -0.6 +0.6 -0.6 +0.6 -0.75 +0.75 ns dqs input high pulse width t dqsh 0.35 0.35 0.35 t ck dqs input low pulse width t dqsl 0.35 0.35 0.35 t ck dqs?dq skew, dqs to last dq valid, per group, per access t dqsq 0.4 0.45 0.5 ns 25, 26 write command to first dqs latching transition t dqss 0.75 1.25 0.75 1.25 0.75 1.25 t ck dqs falling edge to ck rising ? setup time t dss 0.2 0.2 0.2 t ck dqs falling edge from ck rising ? hold time t dsh 0.2 0.2 0.2 t ck half clock period t hp t ch, t cl t ch, t cl t ch, t cl ns 34 data-out high-impedance window from ck/ck# t hz +0.7 +0.7 +0.75 ns 18,42 data-out low-impedance window from ck/ck# t lz -0.7 -0.7 -0.75 ns 18,43 address and control input hold time (fast slew rate) t ih f 0.75 0.75 0.90 ns address and control input setup time (fast slew rate) t is f 0.75 0.75 0.90 ns address and control input hold time (slow slew rate) t ih s 0.8 0.8 1 ns 14 address and control input setup time (slow slew rate) t is s 0.8 0.8 1 ns 14 address and control input pulse width (for each input) t ipw 2.2 2.2 2.2 ns load mode register command cycle time t mrd 12 12 15 ns dq?dqs hold, dqs to first dq to go non-valid, per access t qh t hp - t qhs t hp - t qhs t hp - t qhs ns 25, 26 data hold skew factor t qhs 0.5 0.55 0.75 ns active to precharge command t ras 42 70,000 42 70,000 40 120,000 ns 35 active to read with auto precharge command t rap 18 18 15 ns active to active/auto refresh command period t rc 60 60 60 ns auto refresh command period t rfc 72 72 75 ns 50 active to read or write delay t rcd 18 18 15 ns precharge command period t rp 18 18 15 ns dqs read preamble t rpre 0.9 1.1 0.9 1.1 0.9 1.1 t ck 42 dqs read postamble t rpst 0.4 0.6 0.4 0.6 0.4 0.6 t ck 18 active bank a to active bank b command t rrd 12 12 15 ns dqs write preamble t wpre 0.25 0.25 0.25 t ck dqs write preamble setup time t wpres 0 0 0 ns 20, 21 dqs write postamble t wpst 0.4 0.6 0.4 0.6 0.4 0.6 t ck 19 write recovery time t wr 15 15 15 ns internal write to read command delay t wtr 1 1 1 t ck data valid output window (dvw) n/a t qh - t dqsq t qh - t dqsq t qh - t dqsq ns 25 refresh to refresh command interval t refc 70.3 70.3 70.3 s 23 average periodic refresh interval t refi 7.8 7.8 7.8 s 23 terminating voltage delay to v dd t vtd 0 0 0 ns exit self refresh to non-read command t xsnr 75 75 75 ns exit self refresh to read command t xsrd 200 200 200 t ck
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 57 ?2003 micron technology, inc. table 24: electrical characteristics and recommended ac operating conditions (-75z/-75) notes: 1?5, 14?17, 33, 46; notes appear on pages 59?62; 0c t a +70c; v dd q = +2.5v 0.2v, v dd = +2.5v 0.2v ac characteristics -75z -75 parameter symbol min max min max units notes access window of dqs from ck/ck# t ac -0.75 +0.75 -0.75 +0.75 ns ck high-level width t ch 0.45 0.55 0.45 0.55 t ck 30 ck low-level width t cl 0.45 0.55 0.45 0.55 t ck 30 clock cycle time cl=2.5 t ck (2.5) 7.5 13 7.5 13 ns 45, 52 cl=2 t ck (2) 7.5 13 10 13 ns 45, 52 dq and dm input hold time relative to dqs t dh 0.50 0.50 ns 26, 31 dq and dm input setup time relative to dqs t ds 0.50 0.50 ns 26, 31 dq and dm input pulse width (for each input) t dipw 1.75 1.75 ns 31 access window of dqs from ck/ck# t dqsck -0.75 +0.75 -0.75 +0.75 ns dqs input high pulse width t dqsh 0.35 0.35 t ck dqs input low pulse width t dqsl 0.35 0.35 t ck dqs?dq skew, dqs to last dq valid, per group, per access t dqsq 0.5 0.5 ns 25, 26 write command to first dqs latching transition t dqss 0.75 1.25 0.75 1.25 t ck dqs falling edge to ck rising ? setup time t dss 0.20 0.20 t ck dqs falling edge from ck rising ? hold time t dsh 0.20 0.20 t ck half clock period t hp t ch, t cl t ch, t cl ns 34 data-out high-impedance window from ck/ck# t hz +0.75 +0.75 ns 18,42 data-out low-impedance window from ck/ck# t lz -0.75 -0.75 ns 18,43 address and control input hold time (fast slew rate) t ih f 0.90 0.90 ns address and control input setup time (fast slew rate) t is f 0.90 0.90 ns address and control input hold time (slow slew rate) t ih s 11 ns14 address and control input setup time (slow slew rate) t is s 11 ns14 address and control input pulse width (for each input) t ipw 2.2 2.2 ns load mode register command cycle time t mrd 15 15 ns dq?dqs hold, dqs to first dq to go non-valid, per access t qh t hp - t qhs t hp - t qhs ns 25, 26 data hold skew factor t qhs 0.75 0.75 ns active to precharge command t ras 40 120,000 40 120,000 ns 35 active to read with auto precharge command t rap 20 20 ns active to active/auto refresh command period t rc 65 65 ns auto refresh command period t rfc 75 75 ns 50 active to read or write delay t rcd 20 20 ns precharge command period t rp 20 20 ns dqs read preamble t rpre 0.9 1.1 0.9 1.1 t ck 42 dqs read postamble t rpst 0.4 0.6 0.4 0.6 t ck 18 active bank a to active bank b command t rrd 15 15 ns dqs write preamble t wpre 0.25 0.25 t ck dqs write preamble setup time t wpres 0 0 ns 20, 21 dqs write postamble t wpst 0.4 0.6 0.4 0.6 t ck 19 write recovery time t wr 15 15 ns internal write to read command delay t wtr 1 1 t ck data valid output window (dvw) n/a t qh - t dqsq t qh - t dqsq ns 25 refresh to refresh command interval t refc 70.3 70.3 s 23 average periodic refresh interval t refi 7.8 7.8 s 23 terminating voltage delay to v dd t vtd 0 0 ns exit self refresh to non-read command t xsnr 75 75 ns exit self refresh to read command t xsrd 200 200 t ck
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 58 ?2003 micron technology, inc. table 25: input slew rate derating values for addresses and commands 0c t a +70c; v dd q = +2.5v 0.2v, v dd = +2.5v 0.2v notes: 14; notes appear on pages 59?62 speed slew rate t is t ih units -75/-75z/-75e 0.50 v/ns slew rate < 1.0 v/ns 1.00 1 ns -75/-75z/-75e 0.40 v/ns slew rate < 0.5 v/ns 1.05 1 ns -75/-75z/-75e 0.30 v/ns slew rate < 0.4 v/ns 1.15 1 ns table 26: input slew rate derating values for dq, dqs, and dm 0c t a +70c; v dd q = +2.5v 0.2v, v dd = +2.5v 0.2v notes: 31; notes appear on pages 59-62 speed slew rate t ds t dh units -75/-75z/-75e 0.50 v/ns slew rate < 1.0 v/ns 0.50 0.50 ns -75/-75z/-75e 0.40 v/ns slew rate < 0.5 v/ns 0.55 0.55 ns -75/-75z/-75e 0.30 v/ns slew rate < 0.4 v/ns 0.60 0.60 ns
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 59 ?2003 micron technology, inc. notes 1. all voltages referenced to v ss . 2. tests for ac timing, i dd , and electrical ac and dc characteristics may be conducted at nominal ref- erence/supply voltage levels, but the related spec- ifications and device operation are guaranteed for the full voltage range specified. 3. outputs (except for i dd measurements) measured with equivalent load: 4. ac timing and i dd tests may use a v il -to-v ih swing of up to 1.5v in the test environment, but input timing is still referenced to v ref (or to the crossing point for ck/ck#), and parameter speci- fications are guaranteed for the specified ac input levels under normal use conditions. the mini- mum slew rate for the input signals used to test the device is 1 v/ns in the range between v il (ac) and v ih (ac). 5. the ac and dc input level specifications are as defined in the sstl_2 standard (i.e., the receiver will effectively switch as a result of the signal crossing the ac input level and will remain in that state as long as the signal does not ring back above [below] the dc input low [high] level). 6. v ref is expected to equal v dd q/2 of the transmit- ting device and to track variations in the dc level of the same. peak-to-peak noise (noncommon mode) on v ref may not exceed 2 percent of the dc value. thus, from v dd q/2, v ref is allowed 25mv for dc error and an additional 25mv for ac noise. this measurement is to be taken at the nearest v ref bypass capacitor. 7. v tt is not applied directly to the device. v tt , a sys- tem supply for signal termination resistors, is expected to be set equal to v ref and must track variations in the dc level of v ref . 8. v id is the magnitude of the difference between the input level on ck and the input level on ck#. 9. the value of v ix and v mp are expected to equal v dd q/2 of the transmitting device and must track variations in the dc level of the same. 10. i dd is dependent on output loading and cycle rates. specified values are obtained with mini- mum cycle times at cl = 2.5 for -6/-6t/-6r and - 75, and cl = 2 for -75e/-75z speeds with the out- puts open. 11. enables on-chip refresh and address counters. 12. i dd specifications are tested after the device is properly initialized and is averaged at the defined cycle rate. 13. this parameter is sampled. v dd = +2.5v0.2v, v dd q = +2.5v0.2v, v ref = v ss , f = 100 mhz, t a = 25c, v out (dc) = v dd q/2, v out (peak to peak) = 0.2v. dm input is grouped with i/o pins, reflecting that they are matched in loading. 14. for slew rates < 1 v/ns and 0.5 v/ns. if slew rate is less than 0.5 v/ns, timing must be derated; t is has an additional 50ps per each 100mv/ns reduc- tion in slew rate from the 500mv/ns, while t ih is unaffected. if the slew rate exceeds 4.5 v/ns, func- tionality is uncertain. for -6, -6t, and -6r, slew rates must be greater than or equal to 0.5v/ns. 15. the ck/ck# input reference level (for timing ref- erenced to ck/ck#) is the point at which ck and ck# cross; the input reference level for signals other than ck/ck# is v ref . 16. inputs are not recognized as valid until v ref stabi- lizes. once initialized, including self-refresh mode, v ref must be powered within the specified range. exception: during the period before v ref stabilizes, cke 0.3 x v dd q is recognized as low. 17. the output timing reference level, as measured at the timing reference point indicated in note 3, is v tt . 18. t hz and t lz transitions occur in the same access time windows as data valid transitions. these parameters are not referenced to a specific voltage level, but specify when the device output is no longer driving (hz) or begins driving (lz). 19. the intent of the ?don?t care? state after comple- tion of the postamble is that the dqs-driven sig- nal should either be high, low, or high-z and that any signal transition within the input switch- ing region must follow valid input requirements. if dqs transitions high, above dc v ih (min) then it must not transition low, below dc v ih , prior to t dqsh (min). 20. this is not a device limit. the device will operate with a negative value, but system performance could be degraded due to bus turnaround. 21. it is recommended that dqs be valid (high or low) on or before the write command. the case shown (dqs going from high-z to logic low ) applies when no writes were previously in progress on the bus. if a previous write was in output (v out ) reference point 50 ? v tt 30pf
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 60 ?2003 micron technology, inc. progress, dqs could be high during this time, depending on t dqss. 22. t rc (min) or t rfc (min) for i dd measurements is the smallest multiple of t ck that meets the minimum absolute value for the respective parameter. t ras (max) for i dd measurements is the largest multiple of t ck that meets the maxi- mum absolute value for t ras. 23. the refresh period is 64ms. this equates to an average refresh rate of 7.8125s. however, an auto refresh command must be asserted at least once every 70.3s; burst refreshing or post- ing by the dram controller greater than eight refresh cycles is not allowed. 24. the i/o capacitance per dqs and dq byte/group will not differ by more than this maximum amount for any given device. 25. the data valid window is derived by achieving other specifications: t hp ( t ck/2), t dqsq, and t qh ( t qh = t hp - t qhs). the data valid window derates in direct proportion to the clock duty cycle and a practical data valid window can be derived. the clock is allowed a maximum duty- cycle variation of 45/55, because functionality is uncertain when operating beyond a 45/55 ratio. figure 35, derating data valid window ( t qh - t dqsq), shows data valid window derat- ing curves for duty cycles ranging between 50/ 50 and 45/55. 26. referenced to each output group: x4 = dqs with dq0?dq3; x8 = dqs with dq0?dq7; x16 = ldqs with dq0?dq7; and udq s with dq8?dq15. 27. this limit is actually a nominal value and does not result in a fail value. cke is high during refresh command period ( t rfc [min]) else cke is low (i.e., during standby). 28. to maintain a valid level, the transitioning edge of the input must: a. sustain a constant slew rate from the current ac level through to the target ac level, v il (ac) or v ih (ac). b. reach at least the target ac level. c. after the ac target level is reached, continue to maintain at least th e target dc level, v il (dc) or v ih (dc). 29. the input capacitance per pin group will not dif- fer by more than this maximum amount for any given device. 30. ck and ck# input slew rate must be 1v/ns ( 2v/ns if measured differentially). 31. dq and dm input slew rates must not deviate from dqs by more than 10 percent. if the dq/ dm/dqs slew rate is less than 0.5 v/ns, timing must be derated: 50ps must be added to t ds and 3.750 3.700 3.650 3.600 3.550 3.500 3.450 3.400 3.350 3.300 3.250 3.400 3.350 3.300 3.250 3.200 3.150 3.100 3.050 3.000 2.950 2.900 2.500 2.463 2.425 2.388 2.350 2.313 2.275 2.238 2.200 2.163 2.125 1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4 3.6 3.8 50/50 49.5/50.5 49/51 48.5/52.5 48/52 47.5/53.5 47/53 46.5/54.5 46/54 45.5/55.5 45/55 clock du ty c yc le ns ?? -75 @ t ck = 10ns ?? -8 @ t ck = 10ns ?? -75 @ t ck = 7.5ns ?? -8 @ t ck = 8ns figure 35: derating data valid window ( t qh - t dqsq) examples are for speed grades through -75
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 61 ?2003 micron technology, inc. t dh for each 0.1 v/ns reduction in slew rate. for - 6, -6t and -6r speed grades, slew rate must be 0 .5 v/ns. if slew rate exceeds 4 v/ns, functional- ity is uncertain. 32. v dd must not vary more than four percent if cke is not active while any bank is active. 33. the clock is allowed up to 150ps of jitter. each timing parameter is allowed to vary by the same amount. 34. t hp (min) is the lesser of t cl minimum and t ch minimum actually applied to the device ck and ck# inputs, collectively during bank active. 35. reads and writes with auto precharge are not allowed to be issued until t ras (min) can be satis- fied prior to the internal precharge command being issued. 36. any positive glitch must be less than 1/3 of the clock cycle and not more than +400mv or 2.9v, whichever is less. any negative glitch must be less than 1/3 of the clock cycle and not exceed either -300mv or 2.2v, whichever is more positive. 37. normal output drive curves: a. the full variation in driver pull-down current from minimum to maximum process, temper- ature, and voltage will lie within the outer bounding lines of the v-i curve of figure 36 b. the variation in driver pull-down current within nominal limits of voltage and tempera- ture is expected, but not guaranteed, to lie within the inner bounding lines of the v-i curve of figure 36. c. the full variation in driver pull-up current from minimum to maximum process, temper- ature and voltage will lie within the outer bounding lines of the v-i curve of figure 37. d. the variation in driver pull-up current within nominal limits of voltage and temperature is expected, but not guaranteed, to lie within the inner bounding lines of the v-i curve of figure 37. e. the full variation in the ratio of the maximum to minimum pull-up and pull-down current should be between 0.71 and 1.4, for device drain-to-source voltages from 0.1v to 1.0v, and at the same voltage and temperature. f) the full variation in the ratio of the nominal pull- up to pull-down current should be unity 10 percent, for device drain-to-source voltages from 0.1v to 1.0v. 38. reduced output drive curves: a. the full variation in driver pull-down current from minimum to maximum process, temper- ature, and voltage will lie within the outer bounding lines of the v-i curve of figure 38. b. the variation in driver pull-down current within nominal limits of voltage and tempera- ture is expected, but not guaranteed, to lie within the inner bounding lines of the v-i curve of figure 38. c. the full variation in driver pull-up current from minimum to maximum process, temper- ature and voltage will lie within the outer bounding lines of the v-i curve of figure 39. d. the variation in driver pull-up current within nominal limits of voltage and temperature is expected, but not guaranteed, to lie within the inner bounding lines of the v-i curve of figure 39. figure 36: full drive pull-down characteristics figure 37: full drive pull-up characteristics 0 20 40 60 80 100 120 140 160 0.0 0.5 1.0 1.5 2.0 2.5 v out (v) i out (ma) -200 -180 -160 -140 -120 -100 -80 -60 -40 -20 0 0.0 0.5 1.0 1.5 2.0 2.5 v dd q - v out (v ) i out (m a)
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 62 ?2003 micron technology, inc. figure 38: reduced drive pull-down characteristics figure 39: reduced drive pull-up characteristics e. the full variation in the ratio of the maximum to minimum pull-up and pull-down current should be between 0.71 and 1.4 for device drain-to-source voltages from 0.1v to 1.0v, and at the same voltage and temperature. f. the full variation in the ratio of the nominal pull-up to pull-down current should be unity 10 percent, for device drain-to-source volt- ages from 0.1v to 1.0v. 39. the voltage levels used are derived from a mini- mum v dd level and the referenced test load. in practice, the voltage levels obtained from a properly terminated bus will provide signifi- cantly different voltage values. 40. v ih overshoot: v ih (max) = v dd q + 1.5v for a pulse width 3ns and the pulse width can not be greater than 1/3 of the cycle rate. v il under- shoot: v il (min) = -1.5v for a pulse width 3ns and the pulse width can not be greater than 1/3 of the cycle rate. 41. v dd and v dd q must track each other. 42. this maximum value is derived from the refer- enced test load. in practice, the values obtained in a typical terminated design may reflect up to 310ps less for t hz (max) and the last dvw. t hz (max) will prevail over t dqsck (max) + t rpst (max) condition. t lz (min) will prevail over t dqsck (min) + t rpre (max) condition. 43. for slew rates of greater than 1 v/ns the (lz) tran- sition will start about 310ps earlier. 44. during initialization, v dd q, v tt , and v ref must be equal to or less than v dd + 0.3v. alternatively, v tt may be 1.35v maximum during power-up, even if v dd /v dd q are 0v, provided a minimum of 42 of series resistance is used between the v tt supply and the input pin. 45. the current micron part operates below the slow- est jedec operating frequency of 83 mhz. as such, future die may not reflect this option. 46. for the -6r speed grade, the minimum allowed v dd and v dd q is 2.4v. 47. when an input signal is indicated to be high or low, it is defined as a steady state logic high or low. 48. random addressing changing; 50 percent of data changing at every transfer. 49. random addressing changing; 100 percent of data changing at every transfer. 50. cke must be active (high) during the entire time a refresh command is executed. that is, from the time the auto refresh command is registered, cke must be active at each rising clock edge, until t rfc has been satisfied. 51. i dd 2n specifies the dq, dqs and dm to be driven to a valid high or low logic level. i dd 2q is simi- lar to i dd 2f except i dd 2q specifies the address and control inputs to remain stable. although i dd 2f, i dd 2n, and i dd 2q are similar, i dd 2f is ?worst case.? 52. whenever the operating frequency is altered, not including jitter, the dll is required to be reset fol- lowed by 200 clock cycles before any read com- mand. 0 10 20 30 40 50 60 70 80 0.00.51.01.52. v out (v) i out (ma) -80 -70 -60 -50 -40 -30 -20 -10 0 0.0 0.5 1.0 1.5 2.0 2.5 v dd q - v out (v) i out (ma)
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 63 ?2003 micron technology, inc. note: the above characteristics are specified under best, worst, and nominal process variations/conditions. table 27: normal output drive characteristics voltage (v) pull-down current (ma) pull-up current (ma) nominal low nominal high minimum maximum nominal low nominal high minimum maximum 0.1 6.0 6.8 4.6 9.6 -6.1 -7.6 -4.6 -10.0 0.2 12.2 13.5 9.2 18.2 -12.2 -14.5 -9.2 -20.0 0.3 18.1 20.1 13.8 26.0 -18.1 -21.2 -13.8 -29.8 0.4 24.1 26.6 18.4 33.9 -24.0 -27.7 -18.4 -38.8 0.5 29.8 33.0 23.0 41.8 -29.8 -34.1 -23.0 -46.8 0.6 34.6 39.1 27.7 49.4 -34.3 -40.5 -27.7 -54.4 0.7 39.4 44.2 32.2 56.8 -38.1 -46.9 -32.2 -61.8 0.8 43.7 49.8 36.8 63.2 -41.1 -53.1 -36.0 -69.5 0.9 47.5 55.2 39.6 69.9 -43.8 -59.4 -38.2 -77.3 1.0 51.3 60.3 42.6 76.3 -46.0 -65.5 -38.7 -85.2 1.1 54.1 65.2 44.8 82.5 -47.8 -71.6 -39.0 -93.0 1.2 56.2 69.9 46.2 88.3 -49.2 -77.6 -39.2 -100.6 1.3 57.9 74.2 47.1 93.8 -50.0 -83.6 -39.4 -108.1 1.4 59.3 78.4 47.4 99.1 -50.5 -89.7 -39.6 -115.5 1.5 60.1 82.3 47.7 103.8 -50.7 -95.5 -39.9 -123.0 1.6 60.5 85.9 48.0 108.4 -51.0 -101.3 -40.1 -130.4 1.7 61.0 89.1 48.4 112.1 -51.1 -107.1 -40.2 -136.7 1.8 61.5 92.2 48.9 115.9 -51.3 -112.4 -40.3 -144.2 1.9 62.0 95.3 49.1 119.6 -51.5 -118.7 -40.4 -150.5 2.0 62.5 97.2 49.4 123.3 -51.6 -124.0 -40.5 -156.9 2.1 62.8 99.1 49.6 126.5 -51.8 -129.3 -40.6 -163.2 2.2 63.3 100.9 49.8 129.5 -52.0 -134.6 -40.7 -169.6 2.3 63.8 101.9 49.9 132.4 -52.2 -139.9 -40.8 -176.0 2.4 64.1 102.8 50.0 135.0 -52.3 -145.2 -40.9 -181.3 2.5 64.6 103.8 50.2 137.3 -52.5 -150.5 -41.0 -187.6 2.6 64.8 104.6 50.4 139.2 -52.7 -155.3 -41.1 -192.9 2.7 65.0 105.4 50.5 140.8 -52.8 -160.1 -41.2 -198.2
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 64 ?2003 micron technology, inc. note: the above characteristics are specified under best, worst, and nominal process variations/conditions. table 28: reduced output drive characteristics voltage (v) pull-down current (ma) pull-up current (ma) nominal low nominal high minimum maximum nominal low nominal high minimum maximum 0.1 3.4 3.8 2.6 5.0 -3.5 -4.3 -2.6 -5.0 0.2 6.9 7.6 5.2 9.9 -6.9 -7.8 -5.2 -9.9 0.3 10.3 11.4 7.8 14.6 -10.3 -12.0 -7.8 -14.6 0.4 13.6 15.1 10.4 19.2 -13.6 -15.7 -10.4 -19.2 0.5 16.9 18.7 13.0 23.6 -16.9 -19.3 -13.0 -23.6 0.6 19.9 22.1 15.7 28.0 -19.4 -22.9 -15.7 -28.0 0.7 22.3 25.0 18.2 32.2 -21.5 -26.5 -18.2 -32.2 0.8 24.7 28.2 20.8 35.8 -23.3 -30.1 -20.4 -35.8 0.9 26.9 31.3 22.4 39.5 -24.8 -33.6 -21.6 -39.5 1.0 29.0 34.1 24.1 43.2 -26.0 -37.1 -21.9 -43.2 1.1 30.6 36.9 25.4 46.7 -27.1 -40.3 -22.1 -46.7 1.2 31.8 39.5 26.2 50.0 -27.8 -43.1 -22.2 -50.0 1.3 32.8 42.0 26.6 53.1 -28.3 -45.8 -22.3 -53.1 1.4 33.5 44.4 26.8 56.1 -28.6 -48.4 -22.4 -56.1 1.5 34.0 46.6 27.0 58.7 -28.7 -50.7 -22.6 -58.7 1.6 34.3 48.6 27.2 61.4 -28.9 -52.9 -22.7 -61.4 1.7 34.5 50.5 27.4 63.5 -28.9 -55.0 -22.7 -63.5 1.8 34.8 52.2 27.7 65.6 -29.0 -56.8 -22.8 -65.6 1.9 35.1 53.9 27.8 67.7 -29.2 -58.7 -22.9 -67.7 2.0 35.4 55.0 28.0 69.8 -29.2 -60.0 -22.9 -69.8 2.1 35.6 56.1 28.1 71.6 -29.3 -61.2 -23.0 -71.6 2.2 35.8 57.1 28.2 73.3 -29.5 -62.4 -23.0 -73.3 2.3 36.1 57.7 28.3 74.9 -29.5 -63.1 -23.1 -74.9 2.4 36.3 58.2 28.3 76.4 -29.6 -63.8 -23.2 -76.4 2.5 36.5 58.7 28.4 77.7 -29.7 -64.4 -23.2 -77.7 2.6 36.7 59.2 28.5 78.8 -29.8 -65.1 -23.3 -78.8 2.7 36.8 59.6 28.6 79.7 -29.9 -65.8 -23.3 -79.7
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 65 ?2003 micron technology, inc. figure 40: x4, x8 data output timing ? t dqsq, t qh, and data valid window note: 1. dq transitioning after dqs transition define t dqsq window. dqs transitions at t2 an d at t2n are ?early dqs,? at t3, ?nominal dqs,? and at t3n, ?late dqs.? 2. for a x4, only two dq apply. 3. t dqsq is derived at each dqs clock edge and is not cumulative over time and begins with dqs transition and ends with the last valid dq transition. 4. t qh is derived from t hp: t qh = t hp - t qhs. 5. t hp is the lesser of t cl or t ch clock transition collectively when a bank is active. 6. the data valid window is derived for each dqs transitions and is defined as t qh minus t dqsq. dq (last data valid) dq 2 dq 2 dq 2 dq 2 dq 2 dq 2 dqs 1 dq (last data valid) dq (first data no longer valid) dq (first data no longer valid) all dq and dqs, collectively 6 earliest signal transition latest signal transition t2 t2 t2 t2n t2n t2n t3 t3 t3 t3n t3n t3n ck ck# t1 t2 t3 t4 t2n t3n t qh 4 t hp 5 t hp 5 t hp 5 t qh 4 t qh 4 t hp 5 t hp 5 t hp 5 t qh 4 t dqsq 3 t dqsq 3 t dqsq 3 t dqsq 3 data valid window data valid window data valid window data valid window
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 66 ?2003 micron technology, inc. figure 41: x16 data output timing ? t dqsq, t qh, and data valid window note: 1. dq transitioning after dqs transition define t dqsq window. ldqs defines the lower byte and udqs defines the upper byte. 2. dq0, dq1, dq2, dq3, dq4, dq5, dq6, or dq7. 3. t dqsq is derived at each dqs clock edge and is not cumulative over time and begins with dqs transition and ends with the last valid dq transition. 4. t qh is derived from t hp: t qh = t hp - t qhs. 5. t hp is the lesser of t cl or t ch clock transition collectively when a bank is active. 6. the data valid window is derived for each dqs transition and is t qh minus t dqsq. 7. dq8, dq9, dq10, d11, dq12, dq13, dq14, or dq15. dq (last data valid) 2 dq 2 dq 2 dq 2 dq 2 dq 2 dq 2 ldqs 1 dq (last data valid) 2 dq (first data no longer valid) 2 dq (first data no longer valid) 2 dq0 - dq7 and ldqs, collectively 6 t2 t2 t2 t2n t2n t2n t3 t3 t3 t3n t3n t3n ck ck# t1 t2 t3 t4 t2n t3n t qh 4 t qh 4 t dqsq 3 t dqsq 3 t dqsq 3 t dqsq 3 data valid window data valid window dq (last data valid) 7 dq 7 dq 7 dq 7 dq 7 dq 7 dq 7 udqs 1 dq (last data valid) 7 dq (first data no longer valid) 7 dq (first data no longer valid) 7 dq8 - dq15 and udqs, collectively 6 t2 t2 t2 t2n t2n t2n t3 t3 t3 t3n t3n t3n t qh 4 t qh 4 t qh 4 t qh 4 t dqsq 3 t dqsq 3 t dqsq 3 t dqsq 3 t hp 5 t hp 5 t hp 5 t hp 5 t hp 5 t hp 5 t qh 4 t qh 4 data valid window data valid window data valid window data valid window data valid window upper byte lower byte data valid window
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 67 ?2003 micron technology, inc. figure 42: data output timing ? t ac and t dqsck note: 1. t dqsck is the dqs output window relative to ck and is the ?long-term? component of dqs skew. 2. dq transitioning after dqs transition define t dqsq window. 3. all dq must transition by t dqsq after dqs transitions, regardless of t ac. 4. t ac is the dq output window relative to ck, and is the ?long-term? component of dq skew. 5. t lz (min) and t ac (min) are the first valid signal transition. 6. t hz (max),and t ac (max) are the latest valid signal transition. 7. read command with cl = 2 issued at t0. ck ck# dqs, or ldqs/udqs 2 t0 7 t1 t2 t3 t4 t5 t2n t3n t4n t5n t6 t rpst t lz (min) t dqsck 1 (max) t dqsck 1 (min) t dqsck 1 (max) t dqsck 1 (min) t hz(max) t rpre dq (last data valid) dq (first data valid) all dq values, collectively 3 t ac 4 (min) t ac 4 (max) t lz (min) t hz (max) t2 t2 t2n t3n t4n t5n t2n t2n t3n t3n t4n t4n t5n t5n t3 t4 t4 t5 t5 t2 t3 t4 t5 t3
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 68 ?2003 micron technology, inc. figure 43: data input timing note: 1. t dsh (min) generally occurs during t dqss (min). 2. t dss (min) generally occurs during t dqss (max). 3. write command issued at t0. 4. for x16, ldqs controls the lower byte and udqs controls the upper byte. dqs t dqss t dqsh t wpst t dh t ds t dqsl t dss 2 t dsh 1 t dsh 1 t dss 2 dm dq ck ck# t0 3 t1 t1n t2 t2n t3 di b don?t care transitioning data t wpre t wpres
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 69 ?2003 micron technology, inc. figure 44: initialize and load mode registers note: 1. v tt is not applied directly to the device; however, t vtd should be greater than or equal to zero to avoid device latch-up. v dd q, v tt , and v ref must be equal to or less than v dd + 0.3v. alternatively, v tt may be 1.35v maximum during power-up, even if v dd /v dd q are 0v, provided a minimum of 42 of series resistance is used between the v tt supply and the input pin. once initialized, v ref must always be powered within the specified range. 2. reset the dll with a8 = h while programming the operating parameters. 3. t mrd is required before any command can be applied, and 200 cycles of ck are required before a read command can be issued. 4. the two auto refresh commands at td0 and te0 may be applied prior to the load mode register (lmr) command at ta0. 5. although not required by the micron device, jedec specifies issuing another lmr command (a8 = l) prior to activating any bank. if another lmr command is issued, the same operating parameters must be used as previously issued. 6. pre = precharge command; lmr = load mode register command; ar = auto refresh command; act = active com- mand; ra = row address; and ba = bank address. t vtd 1 cke lvcmos low level dq ba0, ba1 200 cycles of ck 3 load extended mode register load mode register 2 t mrd t mrd t rp t rfc t rfc 5 t is power-up: v dd and ck stable t = 200s high-z t ih dm dqs high-z a0-a9, a11, a12 ra a10 ra all banks ck ck# t ch t cl t ck v tt 1 v ref v dd v dd q command 6 lmr nop pre lmr ar ar act 5 t is t ih ba0 = h, ba1 = l t is t ih t is t ih ba0 = l, ba1 = l t is t ih ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) code code t is t ih code code pre all banks t is t ih t0 t1 ta0 tb0 tc0 td0 te0 tf0 ( ) ( ) don?t care ba ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) t rp ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) -6/6t/6t -75e/75z -75 symbol min max min max min max units t ch 0.45 0.55 0.45 0.55 0.45 0.55 t ck t cl 0.45 0.55 0.45 0.55 0.45 0.55 t ck t ck (2.5) 6 13 7.5 13 7.5 13 ns t ck (2) 7.5 13 7.5 13 10 13 ns t ih f .75 .90 0.90 ns t is f .75 .90 0.90 ns t ih s 0.8 1 1 ns t is s 0.8 1 1 ns t mrd 15 15 15 ns t rfc 72 75 75 ns t rp 18 15 20 ns t vtd 0 0 0 ns -6/6t/6t -75e/75z -75 symbol min max min max min max units
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 70 ?2003 micron technology, inc. figure 45: power-down mode note: 1. once initialized, v ref must always be powered within the specified range. 2. if this command is a precharge (or if the device is alread y in the idle state), then the power-down mode shown is pre- charge power-down. if this command is an active (or if at least one row is already active), then the power-down mode shown is active power-down. 3. no column accesses are allowed to be in progress at the time power-down is entered. ck ck# command valid 2 nop addr cke 1 dq dm dqs valid t ck t ch t cl t is t is t ih t is t is t ih t ih t is enter 3 power-down mode exit power-down mode t refc ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) t0 t1 ta0 ta1 ta2 t2 nop don?t care ( ) ( ) ( ) ( ) valid valid -6/6t/6t -75e/75z -75 symbol min max min max min max units t ch 0.45 0.55 0.45 0.55 0.45 0.55 t ck t cl 0.45 0.55 0.45 0.55 0.45 0.55 t ck t ck (2.5) 6 13 7.5 13 7.5 13 ns t ck (2) 7.5 13 7.5 13 10 13 ns t ih s 0.8 1 1 ns t is s 0.8 1 1 ns -6/6t/6t -75e/75z -75 symbol min max min max min max units
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 71 ?2003 micron technology, inc. figure 46: auto refresh mode note: 1. pre = precharge; act = active; ar = auto refres h; ra = row address; and ba = bank address. 2. nop commands are shown for ease of illustration; other va lid commands may be possible at these times. cke must be active during clock positive transitions. 3. nop or command inhibit are the only commands allowed until after t rfc time; cke must be active during clock posi- tive transitions. 4. ?don?t care? if a10 is high at this point; a10 must be high if more than one bank is active (i.e., must precharge all active banks). 5. dm, dq, and dqs signals are all ?don?t care?/high-z for operations shown. 6. the second auto refresh is not required and is only show n as an example of two back-to-back auto refresh com- mands. ck ck# command 1 nop 2 valid valid nop 2 nop 2 pre cke ra a0-a9, a11, a12 1 a10 1 ba0, ba1 1 bank(s) 4 ba ar nop 2, 3 ar 6 nop 2, 3 act nop 2 one bank all banks ck t ch t cl t is t is t ih t ih t is t ih ra dq 5 dm 5 dqs 5 t rfc 5 t rp t rfc t0 t1 t2 t3 t4 ta0 tb0 ta1 tb1 tb2 don?t care ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) -6/6t/6t -75e/75z -75 symbol min max min max min max units t ch 0.45 0.55 0.45 0.55 0.45 0.55 t ck t cl 0.45 0.55 0.45 0.55 0.45 0.55 t ck t ck (2.5) 6 13 7.5 13 7.5 13 ns t ck (2) 7.5 13 7.5 13 10 13 ns t ih f 0.75 0.90 0.90 ns t is f 0.75 0.90 0.90 ns t ih s 0.8 1 1 ns t is s 0.8 1 1 ns t rfc 72 75 75 ns t rp 18 15 20 ns -6/6t/6t -75e/75z -75 symbol min max min max min max units
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 72 ?2003 micron technology, inc. figure 47: self refresh mode note: 1. clock must be stable until after the self refresh command has been registered. a change in clock frequency is allowed before ta0, provided it is within the specified tck limits. regardless, the clock must be stable before exiting self refresh mode. tha t is, the clock must be cycling within specifications by ta0. 2. nops are interchangeable with deselect commands; ar = auto refresh command. 3. auto refresh is not required at this point, but is highly recommended. 4. device must be in the all banks idle state prior to entering self refresh mode. 5. t xsnr is required before any non-read command can be applied; only nop or deselect commands are allowed until tb1. 6. t xsrd (200 cycles of a valid ck and cke = high) is required before any read command can be applied. 7. as a general rule, any time self refresh mode is exited, the dram may not re-enter the self refresh mode until all rows have been refreshed via the auto refresh command at the distributed refresh rate, t refi, or faster. however, self refresh mode may be re-entered anytime after exiting, if the following conditions are all met: a. the dram had been in the self refresh mode for a minimum of 200ms prior to exiting. b. t xsnr and t xsrd are not violated. c. at least two auto refresh commands are performed duri ng each trefi interval while the dram remains out of self refresh mode. 8. if the clock frequency is changed during self refresh mode, a dll reset is required upon exit. 9. once initialized, v ref must always be powered within the specified range. ck 1 ck# command 2 nop ar addr cke dq dm dqs nop t rp 4 t ch t cl t ck t is t is t ih t is t ih t is enter self refresh mode 7 exit self refresh mode 7 t0 t1 1 ta1 ( ) ( ) don?t care ta0 1 t xsrd 6 ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) nop valid 3 valid ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) t xsnr 5 ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ta2 tb1 tb2 tc1 valid valid valid t is t ih ( ) ( ) ( ) ( ) valid ( ) ( ) ( ) ( ) -6/6t/6t -75e/75z -75 symbol min max min max min max units t ch 0.45 0.55 0.45 0.55 0.45 0.55 t ck t cl 0.45 0.55 0.45 0.55 0.45 0.55 t ck t ck (2.5) 6 13 7.5 13 7.5 13 ns t ck (2) 7.5 13 7.5 13 10 13 ns t ih f 0.75 0.90 0.90 ns t is f 0.75 0.90 0.90 ns t ih s 0.8 1 1 ns t is s 0.8 1 1 ns t rfc 72 75 75 ns t rp 18 15 20 ns t vtd 0 0 0 ns -6/6t/6t -75e/75z -75 symbol min max min max min max units
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 73 ?2003 micron technology, inc. figure 48: bank read - without auto precharge note: 1. do n = data-out from column n ; subsequent elements are provid ed in the programmed order. 2. burst length = 4 in the case shown. 3. disable auto precharge. 4. ?don?t care? if a10 is high at t5. 5. pre = precharge; act = active; ra = row address; and ba = bank address. 6. nop commands are shown for ease of illustration; other commands may be valid at these times. 7. the precharge command can only be applied at t5 if t ras minimum is met. 8. refer to figure 40 on page 65, figure 41 on page 66, and figure 42 on page 67 for detailed dqs and dq timing. ck ck# cke a10 ba0, ba1 t ck t ch t cl t is t is t ih t is t is t ih t ih t ih t is t ih ra t rcd t ras 7 t rc t rp cl = 2 dm t0 t1 t2 t3 t4 t5 t5n t6n t6 t7 t8 dq 1 dqs case 1: t ac ( min) and t dqsck ( min) case 2: t ac ( max) and t dqsck ( max) dq 1 dqs t rpre t rpre t rpst t rpst t dqsck ( min) t dqsck ( max) t lz ( min) t ac ( min) t lz ( min) do n t hz ( max) t ac ( max) do n nop 6 nop 6 command 5 3 act ra ra col n read 2 pre 7 bank x ra ra ra bank x bank x 4 act bank x nop 6 nop 6 nop 6 one bank all banks don?t care transitioning data x4: a0-a9, a11 x8: a0-a9 x16: a0-a8 x4: a12 x8: a11, a12 x16: a9, a11, a12
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 74 ?2003 micron technology, inc. figure 49: bank read - with auto precharge note: 1. do n = data-out from column n; subsequent elements are provid ed in the programmed order. 2. burst length = 4 in the case shown. 3. enable auto precharge. 4. act = active; ra = row address; and ba = bank address. 5. nop commands are shown for ease of illustration; other commands may be valid at these times. 6. the read command can only be applied at t3 if t rap is satisfied at t3. 7. t rp starts only after t ras has been satisfied. 8. refer to figure 40 on page 65, figure 41 on page 66, and figure 42 on page 67 for detailed dqs and dq timing. ck ck# cke a10 ba0, ba1 t ck t ch t cl t is t is t ih t is t is t ih t ih t ih is ih ra t rc t rp 7 cl = 2 dm t0 t1 t2 t3 t4 t5 t5n t6n t6 t7 t8 dq 1 dqs case 1: t ac ( min) and t dqsck ( min) case 2: t ac ( max) and t dqsck ( max) dq 1 dqs t rpre t rpre t rpst t rpst t dqsck ( min) t dqsck ( max) t ac ( min) t lz ( min) do n t hz ( max) t ac ( max) do n nop 5 nop 5 command 4 3 act ra ra col n read 2,6 nop 5 bank x ra ra ra bank x act bank x nop 5 nop 5 nop 5 don?t care transitioning data x4: a0-a9, a11 x8: a0-a9 x16: a0-a8 x4: a12 x8: a11, a12 x16: a9, a11, a12 t ras t lz ( min) t rcd, t rap 6
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 75 ?2003 micron technology, inc. figure 50: bank write - without auto precharge note: 1. di n = data-in from column n ; subsequent elements are prov ided in the programmed order. 2. burst length = 4 in the case shown. 3. disable auto precharge. 4. ?don?t care? if a10 is high at t8. 5. pre = precharge; act = active; ra = row address; and ba = bank address. 6. nop commands are shown for ease of illustration; other commands may be valid at these times. 7. see figure 43, data input timing, on page 68, for detailed dq timing. 8. although not required by the micron device, jedec specifie s that dqs be a valid high, low or some point on a valid transition on or before this clock edge (t3n). ck ck# cke a10 ba0, ba1 t ck t ch t cl t is t is t ih t is t is t ih t ih t ih t is t ih ra t rcd t ras t rp t wr t0 t1 t2 t3 t4 t5 t5n t6 t7 t8 t4n nop 6 nop 6 command 5 3 act ra ra col n write 2 nop 6 one bank all banks bank x pre bank x nop 6 nop 6 nop 6 t dqsl t dqsh t wpst bank x 4 dq 1 dqs dm di b t ds t dh don?t care transitioning data t dqss (nom) t wpre t wpres x4: a0-a9, a11 x8: a0-a9 x16: a0-a8 x4: a12 x8: a11, a12 x16: a9, a11, a12 t3n 8 -6/6t/6t -75e/75z -75 symbol min max min max min max units t ch 0.45 0.55 0.45 0.55 0.45 0.55 t ck t cl 0.45 0.55 0.45 0.55 0.45 0.55 t ck t ck (2.5) 6 13 7.5 13 7.5 13 ns t ck (2) 7.5 13 7.5 13 10 13 ns t ih f 0.75 0.90 0.90 ns t is f 0.75 0.90 0.90 ns t ih s 0.8 1 1 ns t is s 0.8 1 1 ns t mrd 15 15 15 ns t rfc 72 75 75 ns t rp 18 15 20 ns t vtd 0 0 0 ns -6/6t/6t -75e/75z -75 symbol min max min max min max units
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 76 ?2003 micron technology, inc. figure 51: bank write - with auto precharge note: 1. di n = data-out from column n ; subsequent elements are provided in the programmed order. 2. burst length = 4 in the case shown. 3. enable auto precharge. 4. act = active;, ra = row address; and ba = bank address. 5. nop commands are shown for ease of illustration; other commands may be valid at these times. 6. see figure 43, data input timing, on page 68, for detailed dq timing. 7. although not required by the micron device, jedec specifie s that dqs be a valid high, low or some point on a valid transition on or before this clock edge (t3n). ck ck# cke a10 ba0, ba1 t ck t ch t cl t is t is t ih t is t is t ih t ih t ih t is t ih ra t rcd t ras t rp t wr t0 t1 t2 t3 t4 t5 t5n t6 t7 t8 t4n nop 5 nop 5 command 4 3 act ra ra col n write 2 nop 5 bank x nop 5 bank x nop 5 nop 5 nop 5 t dqsl t dqsh t wpst dq 1 dqs dm di b t ds t dh t dqss (nom) don?t care transitioning data t wpres t wpre x4: a0-a9, a11 x8: a0-a9 x16: a0-a8 x4: a12 x8: a11, a12 x16: a9, a11, a12 t3n 7 -6/6t/6t -75e/75z -75 symbol min max min max min max units t ch 0.45 0.55 0.45 0.55 0.45 0.55 t ck t cl 0.45 0.55 0.45 0.55 0.45 0.55 t ck t ck (2.5) 6 13 7.5 13 7.5 13 ns t ck (2) 7.5 13 7.5 13 10 13 ns t dh 0.45 0.5 0.5 ns t ds 0.45 0.5 0.5 ns t dqsh 0.35 0.35 0.35 t ck t dqsl 0.35 0.35 0.35 t ck t dqss 0.75 1.25 0.75 1.25 0.75 1.25 t ck t dss 0.2 0.2 0.2 t ck t dsh 0.2 0.2 0.2 t ck t ih s 0.8 1 1 ns t is s 0.8 1 1 ns t ras 42 70,000 40 120,000 40 120,000 ns t rcd 18 15 20 ns t rp 18 15 20 ns t wpre 0.25 0.25 0.25 t ck t wpres 00 0 ns t wpst 0.4 0.6 0.4 0.6 0.4 0.6 t ck t wr 15 15 15 ns -6/6t/6t -75e/75z -75 symbol min max min max min max units
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 77 ?2003 micron technology, inc. figure 52: write ? dm operation note: 1. di n = data-in from column n ; subsequent elements are provid ed in the programmed order. 2. burst length = 4 in the case shown. 3. disable auto precharge. 4. ?don?t care? if a10 is high at t8. 5. pre = precharge; act = active; ra = row address; and ba = bank address. 6. nop commands are shown for ease of illustration; other commands may be valid at these times. 7. see figure 43, data input timing, on page 68, for detailed dq timing. 8. although not required by the micron device, jedec specifies that dqs be a valid high, low or some point on a valid transition on or before this clock edge (t3n). ck ck# cke a10 ba0, ba1 t ck t ch t cl t is t is t ih t is t is t ih t ih t ih t is t ih ra t rcd t ras t rp t wr t0 t1 t2 t3 t4 t5 t5n t6 t7 t8 t4n nop 6 nop 6 command 5 3 act ra ra col n write 2 nop 6 one bank all banks bank x pre bank x nop 6 nop 6 nop 6 t dqsl t dqsh t wpst bank x 4 dq 1 dqs dm di b t ds t dh don?t care transitioning data t dqss (nom) t wpres t wpre x4: a0-a9, a11 x8: a0-a9 x16: a0-a8 x4: a12 x8: a11, a12 x16: a9, a11, a12 8 t3n -6/6t/6t -75e/75z -75 symbol min max min max min max units t ch 0.45 0.55 0.45 0.55 0.45 0.55 t ck t cl 0.45 0.55 0.45 0.55 0.45 0.55 t ck t ck (2.5) 6 13 7.5 13 7.5 13 ns t ck (2) 7.5 13 7.5 13 10 13 ns t dh 0.45 0.5 0.5 ns t ds 0.45 0.5 0.5 ns t dqsh 0.35 0.35 0.35 t ck t dqsl 0.35 0.35 0.35 t ck t dqss 0.75 1.25 0.75 1.25 0.75 1.25 t ck t dss 0.2 0.2 0.2 t ck t dsh 0.2 0.2 0.2 t ck t ih s 0.8 1 1 ns t is s 0.8 1 1 ns t ras 42 70,000 40 120,000 40 120,000 ns t rcd 18 15 20 ns t rp 18 15 20 ns t wpre 0.25 0.25 0.25 t ck t wpres 00 0 ns t wpst 0.4 0.6 0.4 0.6 0.4 0.6 t ck t wr 15 15 15 ns -6/6t/6t -75e/75z -75 symbol min max min max min max units
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 78 ?2003 micron technology, inc. figure 53: 66-pin plastic tsop (400 mil) note: 1. all dimensionsare in millimeters. 2. package width and length do not include mold protrusi on; allowable mold protrusion is 0.25mm per side. see detail a 0.10 0.65 typ 0.71 10.16 0.08 0.15 0.50 0.10 pin #1 id detail a 22.22 0.08 0.32 0.075 typ +0.03 -0.02 +0.10 -0.05 1.20 max 0.10 0.25 11.76 0.10 0.80 typ 0.10 (2x) gage plane
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 79 ?2003 micron technology, inc. figure 54: 60-ball fbga (16 x 9mm) note: all dimensions are in millimeters. ball #1 id solder ball material: eutectic 63% sn, 37% pb or 62% sn, 36% pb, 2% ag solder ball pad: ? .33mm mold compound: epoxy novolac substrate: plastic laminate ball a1 ball a1 id c l c l 0.850 0.075 0.10 c c .45 60x ? solder ball diameter refers to post reflow condition. the pre-reflow diameter is ? 0.40mm. ball a9 11.00 5.50 0.05 8.00 0.05 16.00 0.10 1.00 typ 0.80 typ 6.40 3.20 0.05 4.50 0.05 9.00 0.10 1.20 max seating plane
256mb: x4, x8, x16 ddr sdram 09005aef8076894f micron technology, inc., reserves the right to change products or specifications without notice.. 256mbddrx4x8x16_2.fm - rev. f 6/03 en 80 ?2003 micron technology, inc ? 8000 s. federal way, p.o. box 6, boise, id 83707-0006, tel: 208-368-3900 e-mail: prodmktg@micron.com, internet: http://www.m icron.com, customer comment line: 800-932-4992 micron, the m logo, and the micron logo are trademarks and/or service marks of micron technology, inc. all other trademarks are the property of their respective owners. figure 55: 60-ball fbga (14 x 8mm) note: all dimensions are in millimeters. data sheet designation this data sheet contains minimum and maximum limits specified over the complete power supply and temperature range for production devices. although considered final, these specifications are subject to change, as further product development and data characterization sometimes occur. pin a1 id 1.20 max mold compound: epoxy novolac substrate: plastic laminate solder ball material: eutectic 62% sn, 36% pb, 2%ag solder ball pad: ? .33mm 14.00 0.10 ball a1 ball a9 pin a1 id 1.00 typ 0.80 typ 7.00 0.05 8.00 0.10 4.00 0.05 3.20 0.05 5.50 0.05 0.850 0.075 seating plane c 11.00 6.40 0.10 c 60x ? 0.45 solder ball diameter refers to post reflow condition. the pre- reflow diameter is ? 0.40 c l c l

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