View IDT70261SL_6877440.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

?2009 integrated device technology, inc. january 2009 dsc 3039/10 1 high-speed 16k x 16 dual-port static ram with interrupt features true dual-ported memory cells which allow simultaneous access of the same memory location high-speed access ? commercial: 15/20/25/35/55ns (max.) ? industrial 20/25ns (max.) low-power operation ? idt70261s active: 750mw (typ.) standby: 5mw (typ.) ? idt70261l active: 750mw (typ.) standby: 1mw (typ.) separate upper-byte and lower-byte control for multiplexed bus compatibility idt70261 easily expands data bus width to 32 bits or more using the master/slave select when cascading more than one device m/ s = h for busy output flag on master, m/ s = l for busy input on slave busy and interrupt flags on-chip port arbitration logic full on-chip hardware support of semaphore signaling between ports fully asynchronous operation from either port ttl-compatible, single 5v (10%) power supply available in 100-pin thin quad flatpack industrial temperature range (-40 o c to +85 o c) is available for selected speeds functional block diagram notes: 1. (master): busy is output; (slave): busy is input. 2. busy and int outputs are non-tri-stated push-pull. idt70261s/l i/o control address decoder memory array arbitration interrupt semaphore logic address decoder i/o control r/ w l busy l a 13l a 0l 3039 drw 01 ub l lb l ce l oe l i/o 8l -i/o 15l i/o 0l -i/o 7l ce l oe l r/ w l sem l int l m/ s r/ w r busy r ub r lb r ce r oe r i/o 8r -i/o 15r i/o 0r -i/o 7r a 13r a 0r r/ w r sem r int r ce r oe r (2) (1,2) (1,2) (2) 14 14
6.42 idt70261s/l high-speed 16k x 16 dual-port static ram with interrupt industrial and commercial temperature ranges 2 pin configurations (1,2,3) pin names notes: 1. all v cc pins must be connected to power supply. 2. all gnd pins must be connected to ground supply. 3. package body is approximately 14mm x 14mm x 1.4mm. 4. this package code is used to reference the package diagram. 5. this text does not indicate orientation of the actual part-marking. description the idt70261 is a high-speed 16k x 16 dual-port static ram. the idt70261 is designed to be used as a stand-alone dual-port ram or as a combination master/slave dual-port ram for 32-bit-or-more word systems. using the idt master/slave dual-port ram approach in 32- bit or wider memory system applications results in full-speed, error-free operation without the need for additional discrete logic. this device provides two independent ports with separate control, address, and i/o pins that permit independent, asynchronous access for reads or writes to any location in memory. an automatic power down feature controlled by ce permits the on-chip circuitry of each port to enter a very low standby power mode. fabricated using idt?s cmos high-performance technology, these devices typically operate on only 750mw of power. the idt70261 is packaged in a 100-pin tqfp. index 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 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 10099989796 95 949392 9190 8988 8786 8584 8382 81 8079 787776 n/c n/c n/c n/c i/o 10l i/o 11l i/o 12l i/o 13l gnd i/o 14l i/o 15l v cc gnd i/o 0r i/o 1r i/o 2r i/o 3r v cc i/o 4r i/o 5r i/o 6r n/c n/c n/c n/c 3039 drw 02 n/c n/c n/c a 5l a 4l a 3l a 2l a 1l a 0l int l gnd m/ s busy r int r a 0r n/c n/c n/c busy l a 1r a 2r a 3r a 4r i / o 9 l i / o 8 l i / o 7 l i / o 6 l i / o 5 l i / o 4 l i / o 3 l i / o 2 l g n d i / o 1 l i / o 0 l o e l v c c r / w l s e m l c e l u b l l b l a 1 2 l a 1 1 l a 1 0 l a 9 l a 8 l a 7 l i / o 7 r i / o 8 r i / o 9 r i / o 1 0 r i / o 1 1 r i / o 1 2 r i / o 1 3 r i / o 1 4 r g n d i / o 1 5 r o e r r / w r s e m r c e r u b r l b r g n d a 1 2 r a 1 1 r a 1 0 r a 9 r a 8 r a 7 r a 6 r a 1 3 l a 1 3 r idt70261pf pn100-1 (4) 100-pin tqfp top view (5) a 6l a 5r , 1 1/16/01 left port right port names ce l ce r chip enable r/ w l r/ w r read/write enable oe l oe r output enable a 0l - a 13l a 0r - a 13r address i/o 0l - i/o 15l i/o 0r - i/o 15r data input/output sem l sem r semaphore enable ub l ub r upper byte select lb l lb r lower byte select int l int r interrupt flag busy l busy r busy flag m/ s master or slave select v cc power gnd ground 3039 tbl 01
6.42 idt70261s/l high-speed 16k x 16 dual-port static ram with interrupt industrial and commercial temperature ranges 3 note: 1. there are eight semaphore flags written to via i/o 0 and read from all i/o's(i/o 0 - i/o 15 ). these eight semaphores are addressed by a 0 - a 2 . maximum operating temperature and supply voltage (1,2) truth table ii ? semaphore read/write control (1) truth table i ? non-contention read/write control recommended dc operating conditions note: 1. a 0l ? a 13l a 0r ? a 13r. notes: 1. v il > -1.5v for pulse width less than 10ns. 2. v term must not exceed vcc + 10%. notes: 1. this is the parameter ta. this is the "instant on"case temperature. grade ambient temperature gnd vcc commercial 0 o c to +70 o c0v 5.0v + 10% industrial -40 o c to +85 o c0v 5.0v + 10% 3039 tbl 02 symbol parameter min. typ. max. unit v cc supply voltage 4.5 5.0 5.5 v gnd ground 0 0 0 v v ih input high voltage 2.2 ____ 6.0 (2 ) v v il input low voltage -0.5 (1 ) ____ 0.8 v 3039 tbl 03 inputs (1) outputs mode ce r/ w oe ub lb sem i/o 8-15 i/o 0-7 hxxxxhhigh-zhigh-zdeselected: power-down x x x h h h high-z high-z both bytes deselecte d llxlhhdata in high-z write to up pe r byte only llxhlhhigh-zdata in write to lowe r by te only llxllhdata in data in write to bo th by te s lhllhhdata out high-z read upper byte only lhlhlhhigh-zdata out read lower byte only lhlllhdata out data out read both bytes xxhxxxhigh-zhigh-zoutputs disabled 3039 tb l 0 4 inputs outputs mode ce r/ w oe ub lb sem i/o 8-1 5 i/o 0-7 hhlxx ldata out data out read data in semaphore flag xhlhhldata out data out read data in semaphore flag h xxxldata in data in write i/o 0 into semaphore flag x xhhldata in data in write i/o 0 into semaphore flag lxxlxl ______ ______ not allowed lxxxll ______ ______ not allowed 3039 tbl 05
6.42 idt70261s/l high-speed 16k x 16 dual-port static ram with interrupt industrial and commercial temperature ranges 4 dc electrical characteristics over the operating temperature and supply voltage range (v cc = 5.0v 10%) note: 1. at vcc < 2.0v, input leakages are undefined. ac test conditions figure 2. output test load (for t lz , t hz , t wz , t ow ) *including scope and jig. figure 1. ac output test load capacitance (1) (t a = +25c, f = 1.0mhz) absolute maximum ratings (1) notes: 1. stresses greater than those listed under absolute maximum ratings may cause permanent 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 operational sections of this specification is not implied. exposure to absolute maximum rating conditions for extended periods may affect reliability. 2. v term must not exceed vcc + 10% for more than 25% of the cycle time or 10ns maximum, and is limited to < 20ma for the period of v term > vcc + 10%. notes: 1. this parameter is determined by device characterization but is not production tested. 2. 3dv represents the interpolated capacitance when the input and output signals switch from 0v to 3v or from 3v to 0v. symbol rating commercial & industrial unit v te rm (2 ) terminal voltage with re sp ect to gnd -0.5 to +7.0 v t bias te m p e r a tu r e under bias -55 to +125 o c t stg storage te m p e r a tu r e -65 to +150 o c i out dc output current 50 ma 3039 tbl 06 symbol parameter conditions (2 ) max. unit c in input capacitance v in = 3dv 9 pf c out output capacitance v out = 3dv 10 pf 3039 tbl 07 symbol parameter test conditions 70261s 70261l unit min. max. min. max. |i li | input leakage current (1) v cc = 5.5v, v in = 0v to v cc ___ 10 ___ 5a |i lo | output leakage current ce = v ih , v out = 0v to v cc ___ 10 ___ 5a v ol output low voltage i ol = 4ma ___ 0.4 ___ 0.4 v v oh output high voltage i oh = -4ma 2.4 ___ 2.4 ___ v 3039 tb l 08 input pulse levels input rise/fall times input timing reference levels output reference levels output load gnd to 3.0v 3ns 1.5v 1.5v figures 1 and 2 3039 tbl 09 3039 drw 04 893 ? 30pf 347 ? 5v data out busy int 893 ? 5pf* 347 ? 5v data out 3039 drw 03 ,
6.42 idt70261s/l high-speed 16k x 16 dual-port static ram with interrupt industrial and commercial temperature ranges 5 dc electrical characteristics over the operating temperature and supply voltage range (1) (v cc = 5.0v 10%) notes: 1. 'x' in part numbers indicates power rating (s or l). 2. v cc = 5v, t a = +25c, and are not production tested. i ccdc = 120ma (typ.) 3. at f = f max , address and control lines (except output enable) are cycling at the maximum frequency read cycle of 1/t rc , and using ?ac test conditions? of input levels of gnd to 3v. 4. f = 0 means no address or control lines change. 5. port "a" may be either left or right port. port "b" is the opposite from port "a". 70261x15 com'l only 70261x20 com'l & ind 70261x25 com'l & ind symbol parameter test condition version typ. (2) max. typ. (2 ) max. typ. (2 ) max. unit i cc dynamic operating current (both po rts active) ce = v il , outputs disabled sem = v ih f = f max (3 ) com'l s l 190 190 325 285 180 180 315 275 170 170 305 265 ma ind s l ____ ____ ____ ____ ____ 180 ____ 315 170 ____ 345 ____ i sb1 standby current (b oth ports - ttl level inputs) ce l = ce r = v ih sem r = sem l = v ih f = f max (3 ) com'l s l 35 35 95 70 30 30 85 60 25 25 85 60 ma ind s l ____ ____ ____ ____ ____ 30 ____ 80 25 ____ 100 ____ i sb2 standby current (one p o rt - ttl le vel inp uts) ce "a" = v il and ce "b" = v ih (5) active port outputs disabled, f=f max (3) sem r = sem l = v ih com'l s l 125 125 220 190 115 115 210 180 105 105 200 170 ma ind s l ____ ____ ____ ____ ____ 115 ____ 210 105 ____ 230 ____ i sb3 full standby current (both ports - all cmos level inputs) both ports ce l and ce r > v cc - 0.2v v in > v cc - 0.2v or v in < 0.2v, f = 0 (4) sem r = sem l > v cc - 0.2v com'l s l 1.0 0.2 15 5 1.0 0.2 15 5 1.0 0.2 15 5 ma ind s l ____ ____ ____ ____ ____ 0.2 ____ 10 1.0 ____ 30 ____ i sb4 full standby current (one p o rt - all cmos le ve l inputs) ce "a" < 0.2v and ce "b" > v cc - 0.2v (5 ) sem r = sem l > v cc - 0.2v v in > v cc - 0.2v or v in < 0.2v active port outputs disabled f = f max (3 ) com'l s l 120 120 195 170 110 110 185 160 100 100 170 145 ma ind s l ____ ____ ____ ____ ____ 110 ____ 185 100 ____ 200 ____ 3039 tbl 10 70261x35 com'l only 70261x55 com'l only symbol parameter test condition version typ. (2 ) max. typ. (2 ) max. unit i cc dynamic operating curre nt (both po rts active) ce = v il , outputs disabled sem = v ih f = f max (3 ) com'l s l 160 160 295 255 150 150 270 230 ma ind s l ____ ____ ____ ____ ____ ____ ____ ____ ma i sb1 standby current (b oth ports - ttl level inputs) ce l = ce r = v ih sem r = sem l = v ih f = f max (3 ) com'l s l 20 20 85 60 13 13 85 60 ma ind s l ____ ____ ____ ____ ____ ____ ____ ____ ma i sb2 standby current (one port - ttl level inputs) ce "a" = v il and ce "b" = v ih (5) active port outputs disabled, f=f max (3) sem r = sem l = v ih com'l s l 95 95 185 155 85 85 165 135 ma ind s l ____ ____ ____ ____ ____ ____ ____ ____ ma i sb3 full standby current (both po rts - all cmos level inputs) both ports ce l and ce r > v cc - 0.2v v in > v cc - 0.2v or v in < 0.2v, f = 0 (4) sem r = sem l > v cc - 0.2v com'l s l 1.0 0.2 15 5 1.0 0.2 15 5 ma ind s l ____ ____ ____ ____ ____ ____ ____ ____ ma i sb4 full standby current (one port - all cmos level inputs) ce "a" < 0.2v and ce "b" > v cc - 0.2v (5 ) sem r = sem l > v cc - 0.2v v in > v cc - 0.2v or v in < 0.2v active port outputs disabled f=f max (3 ) com'l s l 90 90 160 135 80 80 135 110 ma ind s l ____ ____ ____ ____ ____ ____ ____ ____ ma 3039 tbl 1 1
6.42 idt70261s/l high-speed 16k x 16 dual-port static ram with interrupt industrial and commercial temperature ranges 6 notes: 1. transition is measured 0mv from low or high-impedance voltage with output test load (figure 2). 2. this parameter is guaranteed by device characterization, but is not production tested. 3. to access ram, ce = v il and sem = v ih . to access semaphore, ce = v ih and sem = v il . 4. 'x' in part numbers indicates power rating (s or l). ac electrical characteristics over the operating temperature and supply voltage range (4) 70261x15 com'l only 70261x20 com'l & ind 70261x25 com'l & ind unit symbol parameter min.max.min.max.min.max. read cycle t rc read cycle time 15 ____ 20 ____ 25 ____ ns t aa address access time ____ 15 ____ 20 ____ 25 ns t ace chip enable access time (3) ____ 15 ____ 20 ____ 25 ns t ab e byte enable access time (3) ____ 15 ____ 20 ____ 25 ns t aoe output enable access time ____ 10 ____ 12 ____ 13 ns t oh output hold from address change 3 ____ 3 ____ 3 ____ ns t lz output low-z time (1,2) 3 ____ 3 ____ 3 ____ ns t hz output high-z time (1,2) ____ 10 ____ 12 ____ 15 ns t pu chip enable to power up time (2 ) 0 ____ 0 ____ 0 ____ ns t pd chip disable to power down time (2) ____ 15 ____ 20 ____ 25 ns t sop semaphore flag update pulse ( oe or sem )10 ____ 10 ____ 12 ____ ns t sa a semaphore address access time ____ 15 ____ 20 ____ 25 ns 3039 tbl 12a 70261x35 com'l only 70261x55 com'l only unit symbol parameter min. max. min. max. read cycle t rc read cycle time 35 ____ 55 ____ ns t aa address access time ____ 35 ____ 55 ns t ace chip enable access time (3) ____ 35 ____ 55 ns t ab e byte enable access time (3) ____ 35 ____ 55 ns t aoe output enable access time ____ 20 ____ 30 ns t oh output hold from address change 3 ____ 3 ____ ns t lz output low-z time (1,2) 3 ____ 3 ____ ns t hz output high-z time (1,2) ____ 15 ____ 25 ns t pu chip enable to power up time (2 ) 0 ____ 0 ____ ns t pd chip disable to power down time (2) ____ 35 ____ 50 ns t sop semaphore flag update pulse ( oe or sem )15 ____ 15 ____ ns t sa a semaphore address access time ____ 35 ____ 55 ns 3039 tbl 12b
6.42 idt70261s/l high-speed 16k x 16 dual-port static ram with interrupt industrial and commercial temperature ranges 7 notes: 1. timing depends on which signal is asserted last, oe , ce , lb , or ub . 2. timing depends on which signal is de-asserted first ce , oe , lb , or ub . 3. t bdd delay is required only in cases where the opposite port is completing a write operation to the same address location. for simu ltaneous read operations busy has no relation to valid output data. 4. start of valid data depends on which timing becomes effective last t aoe , t ace , t aa or t bdd . 5. sem = v ih . waveform of read cycles (5) timing of power-up power-down t rc r/ w ce addr t aa oe ub, lb 3039 drw 05 (4) t ace (4) t aoe (4) t abe (4) (1) t lz t oh (2) t hz (3, 4) t bdd data out busy out valid data (4) ce u i cc i sb ,
6.42 idt70261s/l high-speed 16k x 16 dual-port static ram with interrupt industrial and commercial temperature ranges 8 ac electrical characteristics over the operating temperature and supply voltage (5) notes: 1. transition is measured 0mv from low or high-impedance voltage with output test load (figure 2). 2. this parameter is guaranteed by device characterization, but is not production tested. 3. to access ram, ce = v il and sem = v ih . to access semaphore, ce = v ih and sem = v il . either condition must be valid for the entire t ew time. 4. the specification for t dh must be met by the device supplying write data to the ram under all operating conditions. although t dh and t ow values will vary over voltage and temperature, the actual t dh will always be smaller than the actual t ow . 5. 'x' in part numbers indicates power rating (s or l). symbol parameter 70261x15 com'l only 70261x20 com'l & ind 70261x25 com'l & ind unit min. max. min. max. min. max. writ e cycle t wc write cycle time 15 ____ 20 ____ 25 ____ ns t ew chip enable to end-of-write (3 ) 12 ____ 15 ____ 20 ____ ns t aw address valid to end-of-write 12 ____ 15 ____ 20 ____ ns t as address set-up time (3) 0 ____ 0 ____ 0 ____ ns t wp write pulse width 12 ____ 15 ____ 20 ____ ns t wr write recovery time 0 ____ 0 ____ 0 ____ ns t dw data valid to end-of-write 10 ____ 15 ____ 15 ____ ns t hz output high-z time (1,2) ____ 10 ____ 12 ____ 15 ns t dh data ho ld time (4 ) 0 ____ 0 ____ 0 ____ ns t wz write enable to output in high-z (1,2) ____ 10 ____ 12 ____ 15 ns t ow output active from end-of-write (1 , 2 ,4 ) 0 ____ 0 ____ 0 ____ ns t swrd sem flag write to read time 5 ____ 5 ____ 5 ____ ns t sp s sem flag contention window 5 ____ 5 ____ 5 ____ ns 3 039 tbl 13a symbol parameter 70261x35 com'l only 70261x55 com'l only unit min. max. min. max. write cycle t wc write cycle time 35 ____ 55 ____ ns t ew chip enable to end-of-write (3 ) 30 ____ 45 ____ ns t aw address valid to end-of-write 30 ____ 45 ____ ns t as address set-up time (3 ) 0 ____ 0 ____ ns t wp write pulse width 25 ____ 40 ____ ns t wr write recovery time 0 ____ 0 ____ ns t dw data valid to end-of-write 15 ____ 30 ____ ns t hz output high-z time (1,2) ____ 15 ____ 25 ns t dh data hold time (4 ) 0 ____ 0 ____ ns t wz write enable to output in high-z (1,2) ____ 15 ____ 25 ns t ow output active from end-of-write (1 , 2 ,4 ) 0 ____ 0 ____ ns t swrd sem flag write to read time 5 ____ 5 ____ ns t sps sem flag contention window 5 ____ 5 ____ ns 3039 tbl 13b
6.42 idt70261s/l high-speed 16k x 16 dual-port static ram with interrupt industrial and commercial temperature ranges 9 timing waveform of write cycle no. 1, r/ w controlled timing (1,5,8) notes: 1. r/ w or ce or ub and lb = v ih during all address transitions. 2. a write occurs during the overlap (t ew or t wp ) of a ce = v il and a r/ w = v il for memory array writing cycle. 3. t wr is measured from the earlier of ce or r/ w (or sem or r/ w ) going v ih to the end of write cycle. 4. during this period, the i/o pins are in the output state and input signals must not be applied. 5. if the ce or sem = v il transition occurs simultaneously with or after the r/ w = v il transition, the outputs remain in the high-impedance state. 6. timing depends on which enable signal is asserted last, ce or r/ w . 7. this parameter is guaranteed by device characterization, but is not production tested. transition is measured 0mv from steady state with the output test load (figure 2). 8. if oe = v il during r/ w controlled write cycle, the write pulse width must be the larger of t wp or (t wz + t dw ) to allow the i/o drivers to turn off and data to be placed on the bus for the required t dw . if oe = v ih during an r/ w controlled write cycle, this requirement does not apply and the write pulse can be as short as the specified t wp . 9. to access ram, ce = v il and sem = v ih . to access semaphore, ce = v ih and sem = v il . t ew must be met for either condition. timing waveform of write cycle no. 2, ce , ub , lb controlled timing (1,5) r/ w t wc t hz t aw t wr t as t wp data out (2) t wz t dw t dh t ow oe address data in (6) (4) (4) (7) ub or lb 3039 drw 07 (9) ce or sem (9) (7) (3) 3039 drw 08 t wc t as t wr t dw t dh address data in r/ w t aw t ew ub or lb (3) (2) (6) ce or sem (9) (9)
6.42 idt70261s/l high-speed 16k x 16 dual-port static ram with interrupt industrial and commercial temperature ranges 10 timing waveform of semaphore read after write timing, either side (1) timing waveform of semaphore write contention (1,3,4) notes: 1. d or = d ol = v il , ce r = ce l = v ih , or both ub & lb = v ih . 2. all timing is the same for left and right ports. port ?a? may be either left or right port. port ?b? is the opposite from por t ?a?. 3. this parameter is measured from r/ w " a" or sem " a" going high to r/ w " b" or sem " b" going high. 4. if t sps is not satisfied, there is no guarantee which side will be granted the semaphore flag. notes: 1. ce = v ih or ub and lb = v ih for the duration of the above timing (both write and read cycle). 2. "data out valid" represents all i/o's (i/o 0 -i/o 15 ) equal to the semaphore value. sem 3039 drw 09 t aw t ew t sop i/o 0 valid address t saa r/ w t wr t oh t ace valid address data in valid data out t dw t wp t dh t as t swrd t aoe read cycle write cycle a 0 -a 2 oe valid (2) sem "a" 3039 drw 10 t sps match r/ w "a" match a 0"a" -a 2"a" side "a" (2) sem "b" r/ w "b" a 0"b" -a 2"b" side (2) "b" ,
6.42 idt70261s/l high-speed 16k x 16 dual-port static ram with interrupt industrial and commercial temperature ranges 11 ac electrical characteristics over the operating temperature and supply voltage range (6,7) notes: 1. port-to-port delay through ram cells from writing port to reading port, refer to "timing wave form of write with port-to-port read and busy (m/ s = v ih )". 2. to ensure that the earlier of the two ports wins. 3. t bdd is a calculated parameter and is the greater of 0, t wdd ? t wp (actual), or t ddd ? t dw (actual). 4. to ensure that the write cycle is inhibited on port "b" during contention on port "a". 5. to ensure that a write cycle is completed on port "b" after contention on port "a". 6. 'x' in part numbers indicates power rating (s or l). symbol parameter 70261x15 com'l only 70261x20 com'l & ind 70261x25 com'l & ind unit min. max. min. max. min. max. busy timing (m/ s =v ih ) t ba a busy access time from address match ____ 15 ____ 20 ____ 20 ns t bda busy disable time from address not matched ____ 15 ____ 20 ____ 20 ns t ba c busy acce ss time from chip enable low ____ 15 ____ 20 ____ 20 ns t bdc busy access time from chip enable high ____ 15 ____ 17 ____ 17 ns t ap s arbitration priority set-up time (2 ) 5 ____ 5 ____ 5 ____ ns t bdd busy disable to valid data (3 ) ____ 18 ____ 30 ____ 30 ns t wh write hold after busy (5 ) 12 ____ 15 ____ 17 ____ ns busy timing (m/ s =v il ) t wb busy input to write (4 ) 0 ____ 0 ____ 0 ____ ns t wh write hold after busy (5 ) 12 ____ 15 ____ 17 ____ ns port-to-port delay timing t wdd write pulse to data delay (1 ) ____ 30 ____ 45 ____ 50 ns t dd d write data valid to read data delay (1 ) ____ 25 ____ 30 ____ 35 ns 3 039 tbl 14a symbol parameter 70261x35 com'l only 70261x55 com'l only unit min. max. min. max. busy timing (m/ s =v ih ) t ba a busy access time from address match ____ 20 ____ 45 ns t bda busy disable time from address not matched ____ 20 ____ 40 ns t ba c busy acce ss time from chip enable low ____ 20 ____ 40 ns t bdc busy access time from chip enable high ____ 20 ____ 35 ns t ap s arbitration priority set-up time (2 ) 5 ____ 5 ____ ns t bdd busy disable to valid data (3 ) ____ 35 ____ 40 ns t wh write hold after busy (5 ) 25 ____ 25 ____ ns busy timing (m/ s =v il ) t wb busy input to write (4 ) 0 ____ 0 ____ ns t wh write hold after busy (5 ) 25 ____ 25 ____ ns port-to-port delay timing t wdd write pulse to data delay (1 ) ____ 60 ____ 80 ns t dd d write data valid to read data delay (1 ) ____ 45 ____ 65 ns 3039 tbl 14b
6.42 idt70261s/l high-speed 16k x 16 dual-port static ram with interrupt industrial and commercial temperature ranges 12 3039 drw 11 t dw t aps addr "a" t wc data out "b" match t wp r/ w "a" data in "a" addr "b" t dh valid (1) match busy "b" t bda valid t bdd t ddd (3) t wdd t baa timing waveform of write with port-to-port read and busy (m/ s = v ih ) (2,4,5) notes: 1. t wh must be met for both busy input (slave) and output (master). 2. busy is asserted on port "b" blocking r/ w "b" , until busy "b" goes high. 3. t wb is only for the ?slave? version. notes: 1. to ensure that the earlier of the two ports wins. t aps is ignored for m/ s = v il (slave). 2. ce l = ce r = v il. 3. oe = v il for the reading port. 4. if m/ s = v il (slave), busy is an input. then for this example busy "a" = v ih and busy "b" input is shown above. 5. all timing is the same for left and right ports. port "a" may be either the left or right port. port "b" is the port opposite from port "a". timing waveform of write with busy (m/ s = v il ) 3039 drw 12 r/ w "a" busy "b" t wp t wb r/ w "b" t wh (2) (3) (1) ,
6.42 idt70261s/l high-speed 16k x 16 dual-port static ram with interrupt industrial and commercial temperature ranges 13 waveform of busy arbitration controlled by ce timing (m/ s = v ih ) (1) waveform of busy arbitration cycle controlled by address match timing (m/ s = v ih ) (1) ac electrical characteristics over the operating temperature and supply voltage range (1) notes: 1. 'x' in part numbers indicates power rating (s or l). notes: 1. all timing is the same for left and right ports. port ?a? may be either the left or right port. port ?b? is the port opposite from port ?a?. 2. if t aps is not satisfied, the busy signal will be asserted on one side or another but there is no guarantee on which side busy will be asserted. 3039 drw 13 addr "a" and "b" addresses match ce "a" ce "b" busy "b" t aps t bac t bdc (2) 3039 drw 14 addr "a" address "n" addr "b" busy "b" t aps t baa t bda (2) matching address "n" symbol parameter 70261x15 com'l only 70261x20 com'l & ind 70261x25 com'l & ind unit min. max. min. max. min. max. interrupt timing t as address set-up time 0 ____ 0 ____ 0 ____ ns t wr write recovery time 0 ____ 0 ____ 0 ____ ns t ins inte rrupt set time ____ 15 ____ 20 ____ 20 ns t inr inte rrupt re se t time ____ 15 ____ 20 ____ 20 ns 3 039 tbl 15a symbol parameter 70261x35 com'l only 70261x55 com'l only unit min. max. min. max. interrupt timing t as address set-up time 0 ____ 0 ____ ns t wr write recovery time 0 ____ 0 ____ ns t ins interrupt set time ____ 25 ____ 40 ns t inr interrupt reset time ____ 25 ____ 40 ns 3039 tbl 15b
6.42 idt70261s/l high-speed 16k x 16 dual-port static ram with interrupt industrial and commercial temperature ranges 14 waveform of interrupt timing (1) truth tables notes: 1. assumes busy l = busy r =v ih . 2. if busy l = v il , then no change. 3. if busy r = v il , then no change. notes: 1. all timing is the same for left and right ports. port ?a? may be either the left or right port. port ?b? is the port opposite from port ?a?. 2. see interrupt truth table. 3. timing depends on which enable signal ( ce or r/ w ) is asserted last. 4. timing depends on which enable signal ( ce or r/ w ) is de-asserted first. truth table iii ? interrupt flag (1) 3039 drw 15 addr "a" interrupt set address ce "a" r/ w "a" t as t wc t wr (3) (4) t ins (3) int "b" (2) 3039 drw 16 addr "b" interrupt clear address ce "b" oe "b" t as t rc (3) t inr (3) int "b" (2) left port right port function r/ w l ce l oe l a 13l -a 0l int l r/ w r ce r oe r a 13r -a 0r int r llx3fffxxxx x l (2) se t right int r flag xxx x xxll3fffh (3) re set right int r flag xxx x l (3) l l x 3ffe x set left int l flag xll3ffeh (2) xxxxxreset left int l flag 3039 tbl 16
6.42 idt70261s/l high-speed 16k x 16 dual-port static ram with interrupt industrial and commercial temperature ranges 15 truth table iv ? address busy arbitration notes: 1. pins busy l and busy r are both outputs when the part is configured as a master. both are inputs when configured as a slave. busy outputs on the idt70261 are push-pull, not open drain outputs. on slaves the busy input internally inhibits writes. 2. "l" if the inputs to the opposite port were stable prior to the address and enable inputs of this port. "h" if the inputs to the opposite port became stable after the address and enable inputs of this port. if t aps is not met, either busy l or busy r = low will result. busy l and busy r outputs can not be low simultaneously. 3. writes to the left port are internally ignored when busy l outputs are driving low regardless of actual logic level on the pin. writes to the right port are internally ignored when busy r outputs are driving low regardless of actual logic level on the pin. truth table v ? example of semaphore procurement sequence (1,2,3) notes: 1. this table denotes a sequence of events for only one of the eight semaphores on the idt70261. 2. there are eight semaphore flags written to via i/o 0 and read from all i/o's (i/o 0 -i/o 15 ). these eight semaphores are addressed by a 0 - a 2 . 3. ce = v ih, sem = v il to access the semaphores. refer to the semaphore read/write control truth table. functional description the idt70261 provides two ports with separate control, address and i/o pins that permit independent access for reads or writes to any location in memory. the idt70261 has an automatic power down feature controlled by ce . the ce controls on-chip power down circuitry that permits the respective port to go into a standby mode when not selected ( ce = v ih ). when a port is enabled, access to the entire memory array is permitted. interrupts if the user chooses the interrupt function, a memory location (mail box or message center) is assigned to each port. the left port interrupt flag ( int l ) is asserted when the right port writes to memory location 3ffe (hex), where a write is defined as ce r = r/ w r = v il per truth table iii. the left port clears the interrupt through access of address location 3ffe when ce l = oe l = v il , r/ w is a "don't care". likewise, the right port interrupt flag ( int r ) is asserted when the left port writes to memory location 3fff (hex) and to clear the interrupt flag ( int r ), the right port must read the memory location 3fff. the message (16 bits) at 3ffe or 3fff is user-defined since it is an addressable sram location. if the interrupt function is not used, address locations 3ffe and 3fff are not used as mail boxes, but as part of the random access memory. refer to truth table iii for the interrupt operation. inputs outputs function ce l ce r a ol -a 13l a or -a 13r busy l (1) busy r (1 ) x x no match h h normal h x match h h normal x h match h h normal l l match (2) (2) write inhibit (3) 3039 tbl 17 functions d0 - d15 left d 0 - d 15 right status no action 1 1 semaphore free left port writes "0" to semaphore 0 1 left port has semaphore token rig ht port writes "0" to semaphore 0 1 no change. right side has no write access to semaphore left port writes "1" to semaphore 1 0 right port obtains semaphore token le ft port writes "0" to semaphore 1 0 no change. left port has no write access to semaphore right port writes "1" to semaphore 0 1 left port obtains semaphore token left port writes "1" to semaphore 1 1 semaphore free right port writes "0" to semaphore 1 0 right port has semaphore token right port writes "1" to semaphore 1 1 semaphore free left port writes "0" to semaphore 0 1 left port has semaphore token left port writes "1" to semaphore 1 1 semaphore free 30 39 tbl 18
6.42 idt70261s/l high-speed 16k x 16 dual-port static ram with interrupt industrial and commercial temperature ranges 16 busy logic busy logic provides a hardware indication that both ports of the ram have accessed the same location at the same time. it also allows one of the two accesses to proceed and signals the other side that the ram is ?busy?. the busy pin can then be used to stall the access until the operation on the other side is completed. if a write operation has been attempted from the side that receives a busy indication, the write signal is gated internally to prevent the write from proceeding. the use of busy logic is not required or desirable for all applications. in some cases it may be useful to logically or the busy outputs together and use any busy indication as an interrupt source to flag the event of an illegal or illogical operation. if the write inhibit function of busy logic is not desirable, the busy logic can be disabled by placing the part in slave mode with the m/ s pin. once in slave mode the busy pin operates solely as a write inhibit input pin. normal operation can be programmed by tying the busy pins high. if desired, unintended write operations can be prevented to a port by tying the busy pin for that port low. the busy outputs on the idt 70261 ram in master mode, are push- pull type outputs and do not require pull up resistors to operate. if these rams are being expanded in depth, then the busy indication for the resulting array requires the use of an external and gate. figure 3. busy and chip enable routing for both width and depth expansion with idt70261 rams. width expansion with busy logic master/salve arrays when expanding an idt70261 ram array in width while using busy logic, one master part is used to decide which side of the ram array will receive a busy indication, and to output that indication. any number of slaves to be addressed in the same address range as the master, use the busy signal as a write inhibit signal. thus on the idt70261 ram the busy pin is an output if the part is used as a master (m/ s pin = v ih ), and the busy pin is an input if the part used as a slave (m/ s pin = v il ) as shown in figure 3. if two or more master parts were used when expanding in width, a split decision could result with one master indicating busy on one side of the array and another master indicating busy on one other side of the array. this would inhibit the write operations from one port for part of a word and inhibit the write operations from the other port for the other part of the word. the busy arbitration, on a master, is based on the chip enable and address signals only. it ignores whether an access is a read or write. in a master/slave array, both address and chip enable must be valid long enough for a busy flag to be output from the master before the actual write pulse can be initiated with either the r/ w signal or the byte enables. failure to observe this timing can result in a glitched internal write inhibit signal and corrupted data in the slave. semaphores the idt70261 is an extremely fast dual-port 16k x 16 cmos static ram with an additional 8 address locations dedicated to binary semaphore flags. these flags allow either processor on the left or right side of the dual- port ram to claim a privilege over the other processor for functions defined by the system designer?s software. as an example, the semaphore can be used by one processor to inhibit the other from accessing a portion of the dual-port ram or any other shared resource. the dual-port ram features a fast access time, and both ports are completely independent of each other. this means that the activity on the left port in no way slows the access time of the right port. both ports are identical in function to standard cmos static ram and can be read from, or written to, at the same time with the only possible conflict arising from the simultaneous writing of, or a simultaneous read/write of, a non- semaphore location. semaphores are protected against such ambiguous situations and may be used by the system program to avoid any conflicts in the non-semaphore portion of the dual-port ram. these devices have an automatic power-down feature controlled by ce , the dual-port ram enable, and sem , the semaphore enable. the ce and sem pins control on-chip power down circuitry that permits the respective port to go into standby mode when not selected. this is the condition which is shown in truth table v where ce and sem are both high. systems which can best use the idt70261 contain multiple processors or controllers and are typically very high-speed systems which are software controlled or software intensive. these systems can benefit from a performance increase offered by the idt70261's hardware sema- phores, which provide a lockout mechanism without requiring complex programming. software handshaking between processors offers the maximum in system flexibility by permitting shared resources to be allocated in varying configurations. the idt70261 does not use its semaphore flags to control any resources through hardware, thus allowing the system designer total flexibility in system architecture. an advantage of using semaphores rather than the more common methods of hardware arbitration is that wait states are never incurred in either processor. this can prove to be a major advantage in very high- speed systems. how the semaphore flags work the semaphore logic is a set of eight latches which are independent of the dual-port ram. these latches can be used to pass a flag, or token, from one port to the other to indicate that a shared resource is in use. the semaphores provide a hardware assist for a use assignment method called ?token passing allocation.? in this method, the state of a semaphore latch is used as a token indicating that shared resource is in use. if the left processor wants to use this resource, it requests the token by setting the latch. this processor then verifies its success in setting the latch by reading it. if it was successful, it proceeds to assume control over the shared resource. if it was not successful in setting the latch, it determines that the right side processor has set the latch first, has the token and is using the shared resource. the left processor can then either repeatedly request 3039 drw 17 master dual port ram busy l busy r ce master dual port ram busy l busy r ce slave dual port ram busy l busy r ce slave dual port ram busy l busy r ce busy l busy r d e c o d e r ,
6.42 idt70261s/l high-speed 16k x 16 dual-port static ram with interrupt industrial and commercial temperature ranges 17 that semaphore?s status or remove its request for that semaphore to perform another task and occasionally attempt again to gain control of the token via the set and test sequence. once the right side has relinquished the token, the left side should succeed in gaining control. the semaphore flags are active low. a token is requested by writing a zero into a semaphore latch and is released when the same side writes a one to that latch. the eight semaphore flags reside within the idt70261 in a separate memory space from the dual-port ram. this address space is accessed by placing a low input on the sem pin (which acts as a chip select for the semaphore flags) and using the other control pins (address, oe , and r/ w ) as they would be used in accessing a standard static ram. each of the flags has a unique address which can be accessed by either side through address pins a 0 ? a 2 . when accessing the semaphores, none of the other address pins has any effect. when writing to a semaphore, only data pin d 0 is used. if a low level is written into an unused semaphore location, that flag will be set to a zero on that side and a one on the other side (see table v). that semaphore can now only be modified by the side showing the zero. when a one is written into the same location from the same side, the flag will be set to a one for both sides (unless a semaphore request from the other side is pending) and then can be written to by both sides. the fact that the side which is able to write a zero into a semaphore subsequently locks out writes from the other side is what makes semaphore flags useful in interprocessor communications. (a thorough discussion on the use of this feature follows shortly.) a zero written into the same location from the other side will be stored in the semaphore request latch for that side until the semaphore is freed by the first side. when a semaphore flag is read, its value is spread into all data bits so that a flag that is a one reads as a one in all data bits and a flag containing a zero reads as all zeros. the read value is latched into one side?s output register when that side's semaphore select ( sem ) and output enable ( oe ) signals go active. this serves to disallow the semaphore from changing state in the middle of a read cycle due to a write cycle from the other side. because of this latch, a repeated read of a semaphore in a test loop must cause either signal ( sem or oe ) to go inactive or the output will never change. a sequence write/read must be used by the semaphore in order to guarantee that no system level contention will occur. a processor requests access to shared resources by attempting to write a zero into a semaphore location. if the semaphore is already in use, the semaphore request latch will contain a zero, yet the semaphore flag will appear as one, a fact which the processor will verify by the subsequent read (see table v). as an example, assume a processor writes a zero to the left port at a free semaphore location. on a subsequent read, the processor will verify that it has written successfully to that location and will assume control over the resource in question. meanwhile, if a processor on the right side attempts to write a zero to the same semaphore flag it will fail, as will be verified by the fact that a one will be read from that semaphore on the right side during subsequent read. had a sequence of read/write been used instead, system contention problems could have occurred during the gap between the read and write cycles. it is important to note that a failed semaphore request must be followed by either repeated reads or by writing a one into the same location. the reason for this is easily understood by looking at the simple logic diagram of the semaphore flag in figure 4. two semaphore request latches feed into a semaphore flag. whichever latch is first to present a zero to the semaphore flag will force its side of the semaphore flag low and the other side high. this condition will continue until a one is written to the same semaphore request latch. should the other side?s semaphore request latch have been written to a zero in the meantime, the semaphore flag will flip figure 4. idt70261 semaphore logic over to the other side as soon as a one is written into the first side?s request latch. the second side?s flag will now stay low until its semaphore request latch is written to a one. from this it is easy to understand that, if a semaphore is requested and the processor which requested it no longer needs the resource, the entire system can hang up until a one is written into that semaphore request latch. the critical case of semaphore timing is when both sides request a single token by attempting to write a zero into it at the same time. the semaphore logic is specially designed to resolve this problem. if simultaneous requests are made, the logic guarantees that only one side receives the token. if one side is earlier than the other in making the request, the first side to make the request will receive the token. if both requests arrive at the same time, the assignment will be arbitrarily made to one port or the other. one caution that should be noted when using semaphores is that semaphores alone do not guarantee that access to a resource is secure. as with any powerful programming technique, if semaphores are misused or misinterpreted, a software error can easily happen. initialization of the semaphores is not automatic and must be handled via the initialization program at power-up. since any semaphore request flag which contains a zero must be reset to a one, all semaphores on both sides should have a one written into them at initialization from both sides to assure that they will be free when needed. using semaphores?some examples perhaps the simplest application of semaphores is their application as resource markers for the idt70261?s dual-port ram. say the 16k x 16 ram was to be divided into two 8k x 16 blocks which were to be dedicated at any one time to servicing either the left or right port. semaphore 0 could be used to indicate the side which would control the lower section of memory, and semaphore 1 could be defined as the indicator for the upper section of memory. to take a resource, in this example the lower 8k of dual-port ram, the processor on the left port could write and then read a zero in to semaphore 0. if this task were successfully completed (a zero was read back rather than a one), the left processor would assume control of the lower 8k. meanwhile the right processor was attempting to gain control d 3039 drw 18 0 d q write d 0 d q write semaphore request flip flop semaphore request flip flop lport rport semaphore read semaphore read ,
6.42 idt70261s/l high-speed 16k x 16 dual-port static ram with interrupt industrial and commercial temperature ranges 18 of the resource after the left processor, it would read back a one in response to the zero it had attempted to write into semaphore 0. at this point, the software could choose to try and gain control of the second 8k section by writing, then reading a zero into semaphore 1. if it succeeded in gaining control, it would lock out the left side. once the left side was finished with its task, it would write a one to semaphore 0 and may then try to gain access to semaphore 1. if semaphore 1 was still occupied by the right side, the left side could undo its semaphore request and perform other tasks until it was able to write, then read a zero into semaphore 1. if the right processor performs a similar task with semaphore 0, this protocol would allow the two processors to swap 8k blocks of dual-port ram with each other. the blocks do not have to be any particular size and can even be variable, depending upon the complexity of the software using the semaphore flags. all eight semaphores could be used to divide the dual- port ram or other shared resources into eight parts. semaphores can even be assigned different meanings on different sides rather than being given a common meaning as was shown in the example above. semaphores are a useful form of arbitration in systems like disk interfaces where the cpu must be locked out of a section of memory during a transfer and the i/o device cannot tolerate any wait states. with the use of semaphores, once the two devices has determined which memory area was ?off-limits? to the cpu, both the cpu and the i/o devices could access their assigned portions of memory continuously without any wait states. semaphores are also useful in applications where no memory ?wait? state is available on one or both sides. once a semaphore handshake has been performed, both processors can access their assigned ram segments at full speed. another application is in the area of complex data structures. in this case, block arbitration is very important. for this application one processor may be responsible for building and updating a data structure. the other processor then reads and interprets that data structure. if the interpreting processor reads an incomplete data structure, a major error condition may exist. therefore, some sort of arbitration must be used between the two different processors. the building processor arbitrates for the block, locks it and then is able to go in and update the data structure. when the update is completed, the data structure block is released. this allows the interpreting processor to come back and read the complete data structure, thereby guaranteeing a consistent data structure.
6.42 idt70261s/l high-speed 16k x 16 dual-port static ram with interrupt industrial and commercial temperature ranges 19 ordering information a power 999 speed a package a process/ temperature range blank commercial (0c to +70c) pf 100-pin tqfp (pn100-1) 15 20 25 35 55 s l standard power low power xxxxx device type 256k (16k x 16) dual-port ram with interrupt 70261 speed in nanoseconds 3039 drw 19 i (1) industrial (-40c to +85c) commercial commercial & industrial commercial & industrial commercial only commercial only , corporate headquarters for sales: for tech support: 6024 silver creek valley road 800-345-7015 or 408-284-8200 408-284-2794 san jose, ca 95138 fax: 408-284-2775 dualporthelp@idt.com www.idt.com the idt logo is a registered trademark of integrated device technology, inc. datasheet document history 1/14/99: initiated datasheet document history converted to new format cosmetic and typographical corrections pages 2 added additional notes to pin configurations 6/4/99: changed drawing format page 1 corrected dsc number 2/18/00: added industrial temperature ranges and removed related notes replaced idt logo changed 200mv in table and waveform notes to 0mv 5/22/00: page 3 clarified t a parameter page 4 increased storage temperature parameter page 5 dc electrical parameters?changed wording from open to disabled 11/20/01: page 2 added date revision for pin configuration page 5 removed industrial temp for standard power 20ns speed from dc electrical characteristics removed industrial temp for low power 25ns speed from dc electrical characteristics removed industrial temp for standard and low power for 35ns & 55ns speeds from dc electrical characteristics pages 6,8,11&13 removed industrial temp for 35ns and 55ns speeds from ac electrical characteristics page 19 removed industrial temp from 35ns and 55ns in ordering information 01/29/09: page 19 removed "idt" from orderable part number note: 1. contact your local sales office for industrial temp range for other speeds, packages and powers.

▲Up To Search▲

Price & Availability of IDT70261SL

	To Download IDT70261SL Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .