Part Number Hot Search : 
R4427S ST62T55 1N5240 2SC236 AD261 D7514G EM48A STV0903B
Product Description
Full Text Search
 

To Download RX78K4 Datasheet File
  If you can't view the Datasheet, Please click here to try to view without PDF Reader .  
　
 

  Datasheet File OCR Text:
 78K/IV SERIES REAL-TIME OS
RX78K/IV
FUNDAMENTAL
(c)
1994
Document No. U10603EJ3V0UM00 (3rd edition) Date Published January 1997 N Printed in Japan
TRON is an abbreviation of The Realtime Operating system Nucleus. ITRON is an abbreviation of Industrial TRON. MS-DOS is a trademark of Microsoft Corporation. IBM-PC/AT is a trademark of IBM Corporation. The other company names and product names appearing in this document are the trademarks of the respective companies.
The information in this document is subject to change without notice. No part of this document may be copied or reproduced in any form or by any means without the prior written consent of NEC Corporation. NEC Corporation assumes no responsibility for any errors which may appear in this document. NEC Corporation does not assume any liability for infringement of patents, copyrights or other intellectual property rights of third parties by or arising from use of a device described herein or any other liability arising from use of such device. No license, either express, implied or otherwise, is granted under any patents, copyrights or other intellectual property rights of NEC Corporation or of others.
M7A 96. 10
Regional Information
Some information contained in this document may vary from country to country. Before using any NEC product in your application, pIease contact the NEC office in your country to obtain a list of authorized representatives and distributors. They will verify:
* * * * *
Device availability Ordering information Product release schedule Availability of related technical literature Development environment specifications (for example, specifications for third-party tools and components, host computers, power plugs, AC supply voltages, and so forth) Network requirements
*
In addition, trademarks, registered trademarks, export restrictions, and other legal issues may also vary from country to country.
NEC Electronics Inc. (U.S.)
Santa Clara, California Tel: 800-366-9782 Fax: 800-729-9288
NEC Electronics (Germany) GmbH
Benelux Office Eindhoven, The Netherlands Tel: 040-2445845 Fax: 040-2444580
NEC Electronics Hong Kong Ltd.
Hong Kong Tel: 2886-9318 Fax: 2886-9022/9044
NEC Electronics (Germany) GmbH
Duesseldorf, Germany Tel: 0211-65 03 02 Fax: 0211-65 03 490
NEC Electronics Hong Kong Ltd. NEC Electronics (France) S.A.
Velizy-Villacoublay, France Tel: 01-30-67 58 00 Fax: 01-30-67 58 99 Seoul Branch Seoul, Korea Tel: 02-528-0303 Fax: 02-528-4411
NEC Electronics (UK) Ltd.
Milton Keynes, UK Tel: 01908-691-133 Fax: 01908-670-290
NEC Electronics (France) S.A.
Spain Office Madrid, Spain Tel: 01-504-2787 Fax: 01-504-2860
NEC Electronics Singapore Pte. Ltd.
United Square, Singapore 1130 Tel: 253-8311 Fax: 250-3583
NEC Electronics Italiana s.r.1.
Milano, Italy Tel: 02-66 75 41 Fax: 02-66 75 42 99
NEC Electronics Taiwan Ltd. NEC Electronics (Germany) GmbH
Scandinavia Office Taeby, Sweden Tel: 08-63 80 820 Fax: 08-63 80 388 Taipei, Taiwan Tel: 02-719-2377 Fax: 02-719-5951
NEC do Brasil S.A.
Sao Paulo-SP, Brasil Tel: 011-889-1680 Fax: 011-889-1689
J96. 8
INTRODUCTION
Thank you for buying NEC's 78K/IV Series Real-time OS RX78K/IV, which is embedded software for the 78K/IV Series. This manual is intended to introduce to the user the general idea of 78K/IV series real-time OS RX78K/IV. [Readers] It is assumed that the readers of this manual have already read the user's manual of the device and has experience in software programming. Note that this package only contains the real-time OS. To use the real-time OS actually, the "CC78K4 series C-compiler" and "RA78K4 series assembler package" are necessary. [Organization] This manual is organized as follows: CHAPTER 1 GENERAL Describes general descriptions and execution environment of this real-time OS. CHAPTER 2 BASIC FUNCTIONS OF RX78K/IV Describes the basic functions of the real-time OS. CHAPTER 3 RX78K/IV BASIC OPERATIONS AND CONTROL BLOCKS Describes the operation and control block of the real-time OS. CHAPTER 4 RX78K/IV SYSTEM CALL LIST Describes system calls supplied by the real-time OS. CHAPTER 5 RX78K/IV RESET OPERATION Describes the operation to initialize this real-time OS. APPENDIX 1 ERROR CODE LIST AND TASK STATUS LIST Describes the return parameters of the system calls and task status. APPENDIX 2 DESCRIPTION IN C LANGUAGE Describes the functions supported by C compiler "CC78K4". APPENDIX 3 SYSTEM CALL LIST Lists the system calls supported by this real-time OS. APPENDIX 4 EXAMPLE OF CYCLIC HANDLER CODING Shows examples of describing cyclic handlers. APPENDIXES 5 AND 6 ESTIMATING MEMORY CAPACITY Describes how to estimate the memory capacity used by this real-time OS, taking examples. APPENDIX 7 STANDBY FUNCTION Describes the method to implement the standby function supplied by the 78K/IV by using this real-time OS. APPENDIX 8 MAXIMUM STACK SIZE USED BY EACH SYSTEM CALL Indicates the stack capacity used when issuing each system call. APPENDIX 9 RESTRICTIONS OF SYMBOL NAMES Explains the symbol names used by this real-time OS.
[Legend] The following symbols are used throughout this manual: ... [] "" `' () _ : Repeat : Can be omitted : Character string : Character string : Character : Important point. Underlined characters in application example must be input as is. : One or more blank : Omission of program description : Delimiter : Back slash
Bold : Character as is
,
: / \
[Related documents] The following table lists the documents (user's manuals) related to this manual.
Document Name 78K/IV series Real-time OS RX78K/IV -Install 78K/IV series Real-time OS RX78K/IV -Debugger RA78K4 Assembler package -Language RA78K4 Assembler package -Operation CC78K4 C compiler -Language CC78K4 C compiler -Operation 78K/IV series -Instruction Document No. U10604EJ3V0UM00 U10364EJ1V0UM00 U10334EJ1V0UM00 U11162EJ1V0UM00
3/4 3/4
EEU-1386
CONTENTS
CHAPTER 1
GENERAL .......................................................................................................................
1
1 1 2 3 4
1.1 Multi-task OS ............................................................................................................................................ 1.2 RX78K/IV ................................................................................................................................................... 1.3 Outline and Features of RX78K/IV .......................................................................................................... 1.4 Configuration and Size of RX78K/IV....................................................................................................... 1.5 Memory Confuguration of RX78K/IV ......................................................................................................
CHAPTER 2
BASIC FUNCTIONS OF RX78K/IV .............................................................................
7
8 9 11 12 13 14 15 16 18 19
2.1 Task State ................................................................................................................................................. 2.1.1 Task state transition ........................................................................................................................ 2.2 Task Manipulation.................................................................................................................................... 2.3 Synchronization and Communication.................................................................................................... 2.3.1 Event flag ........................................................................................................................................ 2.3.2 Semaphore...................................................................................................................................... 2.3.3 Mail box ........................................................................................................................................... 2.4 Interrupt Management ............................................................................................................................. 2.5 Memory Management .............................................................................................................................. 2.6 Time management....................................................................................................................................
CHAPTER 3
RX78K/IV BASIC OPERATIONS AND CONTROL BLOCKS...................................
21
22 22 24 25 25 26
3.1 RX78K/IV Configuration........................................................................................................................... 3.1.1 Flow of overall processing............................................................................................................... 3.1.2 Configuration of ready queue and dispatching................................................................................ 3.2 RX78K/IV Control Block........................................................................................................................... 3.2.1 Control block memory area ............................................................................................................. 3.2.2 Control blocks..................................................................................................................................
CHAPTER 4
RX78K/IV SYSTEM CALL LIST ..................................................................................
27
30 31 32 33 34 35 36 37 38 39 40
4.1 System Calls Related to Task ................................................................................................................. 4.1.1 sta_tsk (Start Task) ......................................................................................................................... 4.1.2 ext_tsk (Exit Task)........................................................................................................................... 4.1.3 ter_tsk (Terminate Task) ................................................................................................................. 4.1.4 chg_pri (Change Task Priority) ichg_pri (Change Task Priority for Interrupt) ................................................................................... 4.1.5 rot_rdq (Rotate Ready Queue) irot_rdq (Rotate Ready Queue for Interrupt).................................................................................... 4.1.6 tsk_sts (Get Task Status) ................................................................................................................ 4.1.7 slp_tsk (Sleep Task)........................................................................................................................ 4.1.8 wai_tsk (Wait for Wakeup Task)...................................................................................................... 4.1.9 wup_tsk (Wakeup Task) iwup_tsk (Wakeup Task for Interrupt) ............................................................................................. 4.1.10 can_wup (Cancel Wakeup Task)...................................................................................................
-i-
4.2 Synchronization and Communication .................................................................................................... 4.2.1 set_flg (Set Eventflag) iset_flg (Set Eventflag for Interrupt)................................................................................................. 4.2.2 clr_flg (Clear Eventflag) ................................................................................................................... 4.2.3 wai_flg (Wait Eventflag)................................................................................................................... 4.2.4 cwai_flg (Wait and Clear Eventflag) ................................................................................................ 4.2.5 pol_flg (Poll Eventflag)..................................................................................................................... 4.2.6 cpol_flg (Poll and Clear Eventflag) .................................................................................................. 4.2.7 sig_sem (Signal Semaphore) isig_sem (Signal Semaphore for Interrupt) ...................................................................................... 4.2.8 wai_sem (Wait on Semaphore) ....................................................................................................... 4.2.9 preq_sem (Poll and Request Semaphore) ...................................................................................... 4.2.10 snd_msg (Send Message to Mailbox) isnd_msg (Send Message to Mailbox for Interrupt) ....................................................................... 4.2.11 rcv_msg (Receive Message from Mailbox) .................................................................................... 4.2.12 prcv_msg (Poll and Receive Message from Mailbox) .................................................................... 4.3 Memory Management............................................................................................................................... 4.3.1 pget_blk (Poll and Get Fixed-Length Memory Block) ...................................................................... 4.3.2 rel_blk (Release Fixed-Length Memory Block)................................................................................ 4.4 Interrupt Processing ................................................................................................................................ 4.4.1 ret_int (Return from Interrupt Handler) ............................................................................................ 4.4.2 ret_wup (Return and Wakeup Task)................................................................................................ 4.5 Version Management ............................................................................................................................... 4.5.1 get_ver (Get Version No.)................................................................................................................ 4.6 Time Management .................................................................................................................................... 4.6.1 act_cyc (Activate Cyclic Handler) iact_cyc (Activate Cyclic Handler for Interrupt)................................................................................
41 42 43 44 45 46 47 48 49 50 51 53 54 55 56 57 58 59 60 62 63 64 65
CHAPTER 5
RX78K/IV RESET OPERATION ...................................................................................
67
68
5.1 Hardware Used .........................................................................................................................................
APPENDIX 1 APPENDIX 2 APPENDIX 3 APPENDIX 4 APPENDIX 5 APPENDIX 6 APPENDIX 7 APPENDIX 8 APPENDIX 9
ERROR CODE LIST AND TASK STATUS LIST...................................................... DESCRIPTION IN C LANGUAGE .............................................................................. SYSTEM CALL LIST.................................................................................................... EXAMPLE OF CYCLIC HANDLER CODING ............................................................ ESTIMATING MEMORY CAPACITY (LARGE MODEL) ........................................... ESTIMATING MEMORY CAPACITY (SMALL MODEL) ........................................... STANDBY FUNCTION.................................................................................................. MAXIMUM STACK SIZE USED BY EACH SYSTEM CALL .................................. RESTRICTIONS ON SYMBOL NAMES ..................................................................... - ii -
69 71 73 75 77 79 81 83 85
LIST OF FIGURES
Figure No.
1-1 1-2 2-1 2-2 2-3 2-4 3-1 3-2 3-3 3-4 4-1 4-2 5-1
Title
Page
5 5 10 16 17 18 22 23 24 25 29 61 67
Memory Structure Example (Large Model).................................................................................................... Memory Structure Example (Small Model) .................................................................................................... RX78K/IV Task State Transition.................................................................................................................... Example of "ret_int" ....................................................................................................................................... Example of "ret_int" ....................................................................................................................................... Memory Pool Configuration ........................................................................................................................... Stack State in Dispatching ............................................................................................................................ Flow of Overall Processing............................................................................................................................ Ready Queue Configuration .......................................................................................................................... Example of Parameters ................................................................................................................................. Entry Address Storage Table ........................................................................................................................ Stack Status When ret_int and ret_wup Are Called ...................................................................................... Reset Routine Branch Program for System Initialization (Large Model) .......................................................
LIST OF TABLES
Table No.
5-1
Title
Page
68
Timer of Each CPU........................................................................................................................................
- iii -
[MEMO]
- iv -
CHAPTER 1
GENERAL
Systems in the field of control equipment are required to respond immediately to changes in external and internal events. The conventional systems have tried to satisfy this requirement by using simple interrupt programs. As the application systems have increasingly become high-performance and sophisticated, however, many problems that cannot be solved only by simple interrupt programs have arisen. In other words, as systems have increasingly become complicated and as the quantity of the programs to be executed has increased, it has been difficult to manage the execution sequence ofthe programs. The real-time operating system (hereafter referred to as the "real-time OS") was developed to cope with this problem. The real-time OS immediately respond to changes in an event and executes the optimum programs in the optimum sequence.
1.1
Multi-task OS
The minimum unit that is executed under the management of the real-time OS is called a task. Multi-tasking is executing two or more tasks simultaneously on one CPU. Actually, however, the CPU can only execute one program at a time. If two or more tasks are selected and executed alternately, for example, at fixed time intervals, however, it seems to the human eye as if these tasks are being executed at the same time. The tasks are executed by taking advantage of opportunities such as time intervals. An OS that has a function to execute tasks in parallel by selecting a task at specific opportunities is called a multi-task OS. A multi-task OS is intended to improve the overall processing ability of the system processing tasks in parallel.
1.2
RX78K/IV
The RX78K/IV is a real-time OS for embedded control applications and has been developed to supply an efficient real-time/multi-task processing environment and to expand the application range of a targeted CPU in the control equipment field, providing complete real-time/multi-task functions. Because it is assumed that the RX78K/IV is embedded in the target system, it has been designed as a compact, high execution speed OS, for implementation in ROM.
1
CHAPTER 1
GENERAL
1.3
Outline and Features of RX78K/IV
(1) Conforms to mITRON Ver.2.01 The system calls of the RX78K/IV conform to the mITRON specifications which are the specifications for a realtime OS for embedded control applications. (2) Real-time/multi-task processing functions Many functions are provided to realize complete real-time/multi-task processing.
* * * * *
Event-driven priority scheduling Three types of synchronization/communication functions Memory management function Interrupt management function Time management function
(3) Designed for ROMization Because the RX78K/IV is an operating system intended for embedded control application, it is designed to be compact. System calls not used can be deleted when configuring a system. (4) Convenient utilities for system configuration Two utilities useful for configuring system are provided.
* *
Configurator High-level language interface
(5) RX78K/IV supports the following cross tools for 78K/IV series.
* *
RA78K4 CC78K4
(6) Two types of memory models supported The RX78K/IV supports the memory models supported by the CC78K4 as follows:
* *
Large model (1M-byte space) : supports location 0fh Small model (64K-byte space) : supports location 00h
2
CHAPTER 1
GENERAL
1.4
Configuration and Size of RX78K/IV
The RX78K/IV consists of the following three subsystems. (1) Nucleus This is the central part of the RX78K/IV. It is embedded in the target system along with the application program and actually carries out real-time/multi-task control. It also performs processing in response to system calls issued from processing tasks. The size of the nucleus differs depending on the system calls to be linked. In the case of the large model, it is about 7K bytes MAX.; in the case of the small model, it is about 5K bytes MAX. (2) C language interface library When the user program is described in C language, system calls are called in the format of C language calling functions. This format, however, differs from the input format the nucleus can understand. The C language interface library is a program that converts system calls written in C into an input format the nucleus can understand and links the processing tasks described in C with the nucleus. The C language interface library is described so that it can be used with the NEC's 78K/IV series C compiler CC78K4. (3) Configurator This is a tool for creating tables with information on the user system necessary for the nucleus. The configurator runs on the development machine and can be used to input and correct the information on the user system necessary for the OS in interactive mode.
3
CHAPTER 1
GENERAL
1.5
Memory Confuguration of RX78K/IV
The memory of the system using RX78K/IV consists of the following: (1) Nucleus (2) Reset routine for system initialization (3) System call entry address storage table (4) OS management area
Note
(5) Initialization information table (6) Object management control block (7) User program [Large model] (1), (2), and (3) above are stored in the internal ROM or external memory space at addresses 0H through 0FFFFH. Because (1), (2), and (3) are relocatable objects, they can located in any area of memory in the above range. (4), (5), and (6) are information tables that are referenced by the reset routine when it initializes the system (these tables are created by the configurator). The user can locate these tables in any area. Note: The area in which (4) and (6) can be located is within 64K bytes with the most significant byte fixed. The area is allocated starting from the address specified by the user. [Small model] (1), (2), and (3) above are stored in the internal ROM or external memory space at addresses 0H through 0FFFFH. Because (1), (2), and (3) are relocatable objects, they can located in any area of memory in the above range. (4), (5), and (6) are information tables that are referenced by the reset routine when it initializes the system (these tables are created by the configurator). Locate (4) and (6) within an 256-byte area at addresses 0F700H through 0F7FFH in the internal RAM area. For the memory map, refer to the User's Manual of the CPU you are using. An example of memory configuration when the RX78K/IV is embedded with the mPD784026 is shown below.
Note
4
CHAPTER 1
GENERAL
Fig. 1-1 Memory Structure Example (Large Model)
FFFFFH SFR FFF00H * Object management block * OS management table FF700H Internal RAM
External memory
10000H * Nucleus * System initialization information table * System call entry address storage table Internal ROM (64KB) * User program (Task & interrupt handler)
00000H
Fig.1-2 Memory Structure Example (Small Model)
0FFFFH SFR 0FF00H
0F7FFH * Object management block * OS management table 0F700H
Internal RAM
* Nucleus * System initialization information table * System call entry address storage table * User program (Task & interrupt handler) Internal ROM
00000H
5
[MEMO]
6
CHAPTER 2
BASIC FUNCTIONS OF RX78K/IV
Because RX78K/IV is a multi-task OS, it can process two or more tasks concurrently. 78K/IV series microcomputer has 8 register banks. With RX78K/IV, bank 0 of these register banks is used by the OS. Tanks can be allocated to registers for high-speed task switching. (For details, refer to 3.1 RX78K/IV Configuration) There are 16 levels of task priorities (0 to 15), with the lowest number assigned the highest priority level. However, priority 0 and priority 1 are reserved for OS. Therefore, priorities to which user tasks can be allocated are limited to the 14 levels of 2 to 15. This chapter describes the following items of the basic functions: (1) Task state (2) Task manipulation (3) Synchronization and communication (4) Interrupt processing (5) Memory management (6) Time management
7
CHAPTER 2
BASIC FUNCTIONS OF RX78K/IV
2.1
Task State
A task can be in any of the following 4 states: (1) RUN state In this state, the task is given the privilege to use the CPU and is under execution. Only one task in the RUN state can exist in the system at a given point of time. (2) READY state A task in the state is ready for execution. All the elements to place the task in the RUN state are ready, but the task in the READY state cannot be executed because a task having the higher priority is currently under execution. (3) WAIT state A task is placed in this state because it has issued a system call to request a resource. A task in this state can be an event flag waiting for an event, a semaphore waiting for a resource, a mail box waiting for a message, or waiting for time. (4) DORMANT state When resetting RX78K/IV, tasks other than the initial one are in a dormant state. When a task is terminated, it enters the pause state.
8
CHAPTER 2
BASIC FUNCTIONS OF RX78K/IV
2.1.1 Task state transition Fig. 2-1 illustrates state transition of a task. Each state transition has the following meaning, and system calls that places a task in one state from another are available. (1) Starting A task is started when it is placed in the READY state from the DORMANT state by a system call. (2) Terminating A task is terminated when it is placed in the DORMANT state from the RUN state by a system call. (3) DISPATCH Dispatching is to select a READY task to be placed in the RUN state. The task that will be placed in the RUN state has the highest priority of the tasks in the READY state. Dispatching is also called scheduling, and the block that executes dispatching or scheduling is called a dispatcher or scheduler. There are 14 levels of task priorities (2 to 15), with the lowest number assigned the highest priority. Others include priorities 0 and 1. However, these cannot be specified for tasks because they are reserved for OS. (4) PREEMPT When a task having a higher priority than that of the task currently executed is placed in the RUN state, the currently executed task is once returned to the READY state. The task placed in the READY state from the RUN state cannot return to the RUN state, unless selected by the dispatcher again. (5) Wait condition If there is a necessity to wait for occurrence of an event, a task enters the WAIT state from the RUN state. A task enters the WAIT state because the task has requested a resource while it was waiting for an event flag to be set but the requested reception has not been found, the task has requested reception of a message but the message has not arrived, the task has requested to wait for a fixed time period, but the period has not yet elapsed, etc. (6) Wait release When a task is released from the WAIT state, it is placed in the READY state. In this case, an event is an occurrence that cancels the factor causing the WAIT state by the system. (7) Forced termination A task is forcibly terminated when it is placed in the DORMANT state from a state other than the RUN state by a system call.
9
CHAPTER 2
BASIC FUNCTIONS OF RX78K/IV
Fig. 2-1 RX78K/IV Task State Transition
DISPATCH READY PREEMPT RUN
Wait release
Wait conditon
WAIT
Start
Forced termination
DORMANT Forced termination Normal termination
10
CHAPTER 2
BASIC FUNCTIONS OF RX78K/IV
2.2
Task Manipulation
RX78K/IV allows the following manipulation of tasks: (1) Starting task All the tasks created when the system is started are placed in the DORMANT state. A task in the DORMANT state cannot be dispatched until it is started. Therefore, it must be placed in the READY state by issuing system call "sta_tsk". (2) Terminating task A task can be terminated by system call "ext_tsk" (normal termination) or "ter_tsk" (forced termination). * Interrupts are enabled when a task has been started for the first time. Disable interrupts for each task.
11
CHAPTER 2
BASIC FUNCTIONS OF RX78K/IV
2.3
Synchronization and Communication
A task is executed under its own environments as an independent program. To execute two or more independent tasks in parallel and thereby to organize one system, it is necessary to control execution flow of the tasks, manage the resources shared by the tasks, and transfer information among tasks. Synchronization and communication are to implement these functions. Synchronization is performed in two modes: wait and mutual exclusion. The wait mode is used, when two tasks play the respective roles of work, to stop the work of one task until the other task has completed its work. In this case, the two tasks have a cooperative relationship. The mutual exclusion mode is used, when two tasks are using a common resource, to prevent one task from using the resource while the other task is using it. In this case, the two tasks are in a competitive relationship. Communication between tasks is for transferring a message between tasks. A task that is to receive the message cannot proceed with processing until it has received the message. Therefore, the communication function can also be used in the place of the synchronization function. As a means to implement synchronization and communication, RX78K/IV provides event flags and semaphores for synchronization, and mail boxes for communication.
12
CHAPTER 2
BASIC FUNCTIONS OF RX78K/IV
2.3.1 Event flag An event flag is used to make a task wait. Since an event flag is a 1-bit flag, it is not ORed or ANDed with the other flags. A task issues system call "wai_flg", "cwai_flg" or "pol_flg", "cpol_flg" to wait for an occurrence of an event. If the event does not occur, the issuing task enters the WAIT state (when wai_flg or cwai_flg is issued). If the task does not enter the WAIT state, an error code is returned (when pol_flg or cpol_flg is issued). To inform the occurrence of the event, system call "set_flg" is issued. The event flag is cleared by system call "clr_flg". An event flag can be used to place two or more tasks in the WAIT state. Therefore, the event flag can queue tasks. In this case, the tasks are released from the WAIT state when "set_flg" is issued once. If at least one task of the tasks placed in the WAIT state specifies clearing the flag (cwai_flg), the event flag is cleared after that task has been released from the WAIT state. Therefore, the tasks following that task are not released from the WAIT state.
13
CHAPTER 2
BASIC FUNCTIONS OF RX78K/IV
2.3.2 Semaphore A semaphore is used to mutually exclude tasks. The semaphore is a measurement that can check whether currently usable resources exist, or manage the number of resources. The number of requested resources of the wait manipulation (P) and signal manipulation (V) instructions for a semaphore is fixed to 1. If a task needs a resource, it performs resource acquisition manipulation (P instruction) by issuing system call "wai_sem", "preq_sem". If the number of resources is 1 or more, the number of resources of the semaphore is decremented by one. If the number of resources is 0, the resource requesting task is placed in the WAIT state (wai_sem), or if the task is not placed in the WAIT state, an error code is returned (preq_sem). If the task does not need the resource any more, it executes resource return manipulation (V instruction) by issuing system call "sig_sem". As a consequence, the number of resources of the semaphore is incremented by one. If there are tasks waiting for a resource at this time, the task first placed in the WAIT state is released. A task waits for a semaphore on a FIF0 basis only.
14
CHAPTER 2
BASIC FUNCTIONS OF RX78K/IV
2.3.3 Mail box A mail box transmits messages between tasks and has a queue of tasks waiting for reception of a message and a queue of messages waiting to be transmitted. A task can request reception of a message from a mail box by issuing system call "rcv_msg" or "prcv_msg". If the message has not arrived after "rcv_msg" has been issued, the task enters the WAIT state and queued to the mail box. If the task has issued "prcv_msg", it does not enter the WAIT state, but an error code is returned. A task can also send a message to a mail box by issuing system call "snd_msg". If there is a task waiting for the message, that task is released from the WAIT state and the message is transmitted to that task. If there is no waiting task, the message is queued. Messages and tasks are queued on a FIF0 basis only.
15
CHAPTER 2
BASIC FUNCTIONS OF RX78K/IV
2.4
Interrupt Management
Interrupt management is for managing processing that is driven taking an interrupt as an event. A processing routine that is vectored by an interrupt is called an interrupt handler, which is independent of tasks. There are functions to set or exit execution from the interrupt handler. To terminate the interrupt handler and pass control to a task, system calls "ret_int" and "ret_wup" are used. To issue "ret_int" from an interrupt handler occupying the register bank, select the register bank of the task executed before the interrupt has occurred, and then call "ret_int". Because RX78K/IV does not initialize each interrupt source, each source must be initialized by the user task. Fig. 2-2 and 2-3 illustrate the flow of control when a task in the WAIT state is waken up by an event flag in an interrupt handler. If a task in the WAIT state is waken up an interrupt handler, system calls "ret_int" and "ret_wup" return control to the state of a task under execution when the interrupt has occurred, if the priority of the task to be waken up is lower than the priority of the task under execution when the interrupt has occurred. If the task to be waken up has a higher priority than that of the task under execution, control is passed to the task to be waken up. Fig. 2-2 illustrates flow of control if task A has a higher priority than task B. Caution * System calls cannot be issued during NMI interrupt processing.
* Please note that RX78K/IV does not support multiple interrupt among the interrupt handlers
which are set for interrupt priority 3 (lowest level). Neither does it support them with the timer processing. <1> Task B has issued system call "wai_tsk" and is now in the WAIT state. <2> Task A is under execution (has the highest priority of the tasks in the READY state). <3> An interrupt occurs while task A is executed, and processing is passed to the interrupt handler. <4> System call "iset_flg" is issued in the interrupt handler and task B is waken up. <5> System call "ret_int" is issued in the interrupt handler. <6> Because task A has a priority higher than that of task B, processing is returned to task A. Fig. 2-2 Example of "ret_int"
Task A (PR1=2) Interrupt handler Task B (PRI=3)
<1> wai_flg <2>
<3>
<4> iset_flg (Wakes up task B)
Interrupt
<6>
<5> ret_int
16
CHAPTER 2
BASIC FUNCTIONS OF RX78K/IV
Fig. 2-3 shows an example where task A has a lower priority than task B. <1> Task B has issued system call "wai_flg" and is now in the WAIT state. <2> Task A is under execution (has the highest priority of the tasks in the READY state). <3> An interrupt occurs while task A is executed, and processing is passed to the interrupt handler. <4> System call "iset_flg" is issued in the interrupt handler, and task B is waken up. <5> System call "ret_int" is issued in the interrupt handler. <6> Because task B has a priority higher than task A, processing is passed to task B. Fig. 2-3 Example of "ret_int"
Task A (PRI=3) Interrupt handler Task B (PRI=2)
<2>
<1> wai_flg <3> <4> iset_flg (Wakes up task B)
Interrupt <6>
<5> ret_int
17
CHAPTER 2
BASIC FUNCTIONS OF RX78K/IV
2.5
Memory Management
RX78K/IV performs dynamic memory management based on a memory block of fixed size. This means that a task acquires memory when necessary, and releases it when unnecessary. By using this feature, it is not necessary to acquire a memory area in advance for even two or more tasks, so that the memory can be efficiently used. The memory block of RX78K/IV is dynamically acquired by a system call under execution by the system, and is returned after it has been used and is no longer necessary. If one memory block cannot be acquired, state transition of a task does not take place, but only an error code is returned. The size of one memory block is fixed to a value specified on system creation. Usually, an acquired memory block is used as a message area, in which case the first 2 bytes with the large model, the first 1 byte with the small model, are used as a queue link area. Therefore, the area that can be used as a message area is the area excluding link area.
Fig. 2-4 Memory Pool Configuration
Memory pool first address
Queue area Queue area Queue area
Free block management area Large model : 4 bytes Small model : 2 bytes
Size of 1 memory block Memory block
Queue area
Large model : 2 bytes Small model : 1 byte
Memory block
Queue area
=0 (Queue area of last memory block)
Memory block
Caution
When using a memory block as a message area, please make the size of the memory block a multiple of 2. Operation is not guaranteed if the size is not a multiple of 2.
18
CHAPTER 2
BASIC FUNCTIONS OF RX78K/IV
2.6
Time management
Time management refers to delayed wake up of tasks and the running of cyclic handlers. Delayed wake up tasks means performing wake up processing on a task after the elapsing of a specified amount of time, and is implemented by means of the "wai_task" system call. Running of cyclic handlers means managing the running of handlers as interrupt processes as specified time intervals, and is implemented by means of the "act_cyc(iact_cyc)" system call. In RX78K/IV, one of the CPU's 16-bit timer/counter units is used as the interval timer. By allocating vector table of the timer dispatch routine provided by the OS to this timer (?tmdsp), this routine can be periodically run. In the timer dispatch routine, the waiting time of a task that has issued the (wai_tsk) system call, or the waiting time of a cyclic handler is counted down, and when the specified time has elapsed, the task is awakened, or the cyclic handler is run. Regarding the actual state transition, a task that has issued "wai_tsk" goes from the WAIT state to the READY state, whereas a cyclic handler is called directly from the timer dispatch routine.
19
[MEMO]
20
CHAPTER 3
RX78K/IV BASIC OPERATIONS AND CONTROL BLOCKS
This chapter describes the basic operations of a system running RX78K/IV and the control block configuration managed by RX78K/IV.
21
CHAPTER 3
RX78K/IV BASIC OPERATIONS AND CONTROL BLOCKS
3.1
RX78K/IV Configuration
3.1.1 Flow of overall processing RX78K/IV uses register bank 0 of the 8 register banks of the 78K/IV series microcomputers. For user tasks, multiple tasks can be allocated to register bank 1, and one task each to register bank 2 to 7. The tasks allocated to register banks 2 to 7 can realize high-speed task switching, because with them, it is unnecessary to save the registers when tasks are switched over during execution. An example method for allocating register banks is shown below. Example 1: With 6 tasks Register bank 1 : None Register banks 2 to 7 : One task each Example 2: With 6 tasks Register bank 1 : 3 tasks Register banks 2 to 4 : One task each Register banks 5 to 7 : For interrupting Example 3: With 10 tasks Register bank 1 : 4 tasks Register banks 2 to 7 : One task each The task area is required for each task; therefore, when performing a task, the stack area of the task is used. The interrupt handler uses the stack area of the task being performed when an interrupt occurred. The stack state in dispatching is shown below. Fig. 3-1 Stack State in Dispatching
When tasks are allocated to register bank 1 High Stack area When tasks are allocated to register bank 2 to 7 High Stack area
PC15-8 PSWH R15 R13
PC19-16 PC7-0 PSWL R14
PC15-8 PSWH
PC19-16 PC7-0 PSWL
R
R2 R0
Low
Low
22
CHAPTER 3
RX78K/IV BASIC OPERATIONS AND CONTROL BLOCKS
Register bank 1 is shared by multiple tasks. Therefore, dispatching or preempting make it necessary for registers to be saved or restored. This causes the overhead of these tasks to be slightly larger than the tasks allocated to register banks 2 to 7. Fig. 3-2 shows the flow of the processing to be performed since the system call has been issued until control is returned to the bank. Fig. 3-2 Flow of Overall Processing
Task
RX78K/IV
Issurance of system call Save registers, etc. (when using RB1)
Processing system call
Selected task
Dispatch
23
CHAPTER 3
RX78K/IV BASIC OPERATIONS AND CONTROL BLOCKS
3.1.2 Configuration of ready queue and dispatching When RX78K/IV passes CPU execution privilege to a task, it searches for a task having the highest priority in the READY state. At this time, RX78K/IV references a ready queue. RX78K/IV has 16 ready queues each corresponding to 16 priority levels (0 to 15). The task chained to the head of a ready queue has the highest priority of the tasks in the queue, and the task chained to the tail of the queue has the lowest priority. Among these priority levels, levels 2 to 15 can be specified for a task. RX78K/IV searches the ready queues from the one having the highest priority for a task to be placed in the RUN state. However, if there is no executable user task at that time, it sets the CPU in the HALT mode. To resume execution of a user task, therefore, an interrupt must be used. The stack area at that time becomes the user stack area. Fig. 3-3 shows the configuration of the ready queue. Fig. 3-3 Ready Queue Configuration
Ready queue
TCB1 Queue area
TCB2 Queue area
TCBn Queue area
TOP LAST
Information particular to the task
Information particular to the task
Information particular to the task
24
CHAPTER 3
RX78K/IV BASIC OPERATIONS AND CONTROL BLOCKS
3.2
RX78K/IV Control Block
RX78K/IV has control blocks to manage each object. The control blocks are created by the user at time of configuration, and RX78K/IV uses these blocks for system calls or for management. Therefore, the state of the control blocks can be always monitored by the user task. The types of RX78K/IV control blocks are as follows: <1> TCB (Task Control Block) <2> EVT (Eventflag) <3> SEM (Semaphore) <4> MBOX (Mail Box) <5> MPL (Memory Pool) <6> HCB (Cyclic Handler Control Block) 3.2.1 Control block memory area As described above, the control blocks are created by the user at time of configuration with RX78K/IV. Therefore, all parameters are passed to system calls (related to control blocks) by specifying an address by using a symbol name. Fig. 3-4 shows an example of parameters. Fig. 3-4 Example of Parameters
TCB TSKID_1 Queue area EVTID_1
EVT
Queue area
flgid = EVTID_1
takid = TSKID_1 xxxid = Starting adderss of target object
25
CHAPTER 3
RX78K/IV BASIC OPERATIONS AND CONTROL BLOCKS
3.2.2 Control blocks (1) Task control block (TCB) This control block is used by RX78K/IV to manage tasks. One control block of this type is assigned to each task. One TCB is 10 bytes long with the large model, and 8 bytes long with the small model. (2) Event flag (EVT) An event flag is a block that manages events that are used to synchronize tasks or make tasks wait. One event flag is 4 bytes long with the large model, and 2 bytes long with the small model. * If two or more tasks are waiting when the event flag is set, all the WAIT tasks enter the READY state. However, if a task exists that has issued "cwai_flg" and has entered the WAIT state, the flag is cleared after that task has been released from the WAIT state. After that, task state transitions do not take place. (3) Semaphore (SEM) A semaphore is a resource management block that is used to synchronize or mutually exclude tasks. One semaphore is 4 bytes long with the large model, and 2 bytes long with the small model. (4) Mail box (MBOX) A mail box is a control block that manages message communication between tasks. One mail box is 4 bytes long with the large model, and 2 bytes long with the small model. (5) Memory pool (MPL) The memory pool manages free memory blocks. Normally, memory blocks are used as message areas. When use it as a message area, be sure to set the size of one memory block to a multiple of 2. Even in cases other than messages, it is possible to secure only the portion of the memory blocks required for the relevant purpose. The size of the memory pool is the total of the free block management area and the memory blocks. The size of the free block management area is 4 bytes long with the large model, and 2 bytes long with the small model. (6) Cyclic handler control block (HCB) Cyclic handler control blocks are used by RX78K/IV to manage cyclic handlers. One cyclic handler is given one control block. The size of each cyclic handler control block is 10 bytes long with the large model, and 8 bytes long with the small model.
26
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
This chapter describes the following items of each system calls: [Function]: Outline of the function of the system call [Remarks]: Describes the function of the system call [System call ID number]: Number particular to system call when the assembler calls the system call [Parameter]: Describes the name, data size, and explanation of each parameter. [Return parameter]: A list of return values that may occur as a result of issuance of the system call. The return value is returned as a function value of the system call in the case of the C language, and to register C in the case of the assembler. Since no abnormal termination processing is performed for all the system calls, add abnormal termination processing by referring to the value of the return parameter. [Assembler format]: Describes which register is used for output parameter, and how to handle an input parameter when the system call is issued in the assembler. For the system call called from an interrupt handler, describes which register is used as an input parameter. The symbols described in the assembler format have the following addresses: [Large model] bnk0_b = 0FFEF3H, bnk0_e = 0FFEFCH, [Small model] bnk0_b = 0FEF3H, bnk0_e = 0FEFCH The system call which can be issued from an interrupt handler uses the register bank of that time. The following is described in the assembler format: [Large model] Example [Small model] Example E, UP, VP E, UUP, VVP bnk0_vp = 0FEF8H, bnk0_up = 0FEFAH, bnk0_vp = 0FFEF8H, bnk0_d = 0FFEFDH bnk0_up = 0FFEFAH,
27
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
[C format]: Description format used when the system call is issued in the C language and the data type of the parameter
Interface with C language
The high-level language supported in developing an application program is the C language. To issue a system call in the C language, an assembler routine is necessary for interfacing with the OS. Therefore, the interface routine corresponding to the system call used must be linked with each task. The format of the system call in the C language is as follows: ret = ([],...); ret : function return value (char type) : system call name : input parameter
The data type of each parameter and size are as follows. char unsigned short char* : 8-bit integer : 16-bit integer : 24-bit pointer (large model) 16-bit pointer (small model)
Interface with assembler
To issue a system call in the assembler, set parameters to the relevant register of register bank 0 as follows. Example of sta_tsk issuance (large model)
MOV MOVW MOV CALLT
BNK0_REG1, #system call ID number BNK0_REG2, #parameter 1 (lower 16 bits) BNK0_REG3, #parameter 1 (higher 8 bits) [40H]
Example of sta_tsk issuance (small model)
MOV MOVW CALLT
BNK0_REG1, #system call ID number BNK0_REG2, #parameter 1 [40H]
The entry address of branch processing to branch to the system call is set to 40H. The branch processing module takes out the entry address of each system call from a table created by the configurator and branches. The configuration of the entry address storage table of system calls is as follows:
28
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
Fig. 4-1 Entry Address Storage Table
sta_tsk ext_tsk . . . . 00H get_ver ... If system call is not selected ... Entry address of target system call
Be sure to directly call the following i_ system call issued from the interrupt handler, without going through the branching module. The values in the brackets indicate the addresses of the CALLT table. However, addresses corresponding to unused system calls can be used by users. ichg_pri (42H), irot_rdq (44H), iwup_tsk (46H), iset_flg (48H), isig_sem (4AH), isnd_msg (4CH) The ret_int and ret_wup system calls are branched out to system calls directly by the BR command.
Differences between "_" and "i_" system calls
System call "i_" is started by an interrupt handler and is not dispatched its own. This system call is dispatched when "ret_int" has been issued that returns execution from the interrupt handler, or "ret_wup" that returns execution from the interrupt handler and wakes up a task. When a system call is recovered from the interrupt handler with the RETI command, dispatching occurs in the next system call.
29
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.1
System Calls Related to Task
The following system calls are related to tasks: (1) sta_tsk (2) ext_tsk (3) ter_tsk (4) chg_pri ichg_pri (5) rot_rdq irot_rdq (6) tsk_sts (7) slp_tsk (8) wai_tsk (9) wup_tsk iwup_tsk (10) can_wup Starts task Normally terminates task itself Forcibly terminates another task Changes the tasks priority Changes the tasks priority Rotates specified priority ready queue Rotates specified priority ready queue Checks the tasks state Places the tasks in WAIT state Places the tasks in WAIT state for fixed time Wakes up the task Wakes up the task (when used in interrupt handler) Makes the task wake-up request invalid
30
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.1.1 sta_tsk (Start Task)
[Function] Starts a task by placing it in the READY state from the DORMANT state. [Remarks] This system call starts the task specified by tskid. As a result, the task enters the READY state from the DORMANT state. This system call must not be issued to a task that is not in the DORMANT state. If issued, error code "E_NODMT" is returned. To start a task for the first time, or to restart a task that has been once terminated, processing is started from the start address of the task, and the value of the stack pointer is set to the initial value. The values of the other registers are undefined. A task to which the "sta_tsk" system call is to be issued enables interrupts. Disable interrupts for each task. [System call ID number] sta_tsk = 0 [Parameter] tskid (Task Identifier) Task ID (TCB top address) - 24 bits (large model) - 16 bits (small model) [Return parameter] E_OK E_NODMT [Assembler format] [Large model] MOV MOVW MOV CALLT bnk0_b, #0 bnk0_up, #tskid bnk0_d, #tskid [40H] : C register= return parameter [C format] ret = sta_tsk(tskid); char *tskid; [Small model] MOV MOVW CALLT bnk0_b, #0 bnk0_up, #tskid [40H] : C register= return parameter Normal termination Specified task is not in DORMANT state
31
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.1.2 ext_tsk (Exit Task)
[Function] Normally terminates the task itself and places the task in the DORMANT state from the RUN state. [Remarks] This system call normally terminates the task that issues this system call itself. As a result, the task enters the DORMANT state from the RUN state. To restart by the "sta_tsk" system call the task that has entered the DORMANT state by issuing the "ext_tsk" system call, the start address and stack pointer are returned to the initial values. The wakeup request counter is cleared to 0. The task does not automatically release the resource it has acquired before the "ext_tsk" system call is issued. Release the resources before issuing this system call. [System call ID number] ext_tsk = 1 [Parameter] None [Return parameter] None (Control is not returned to the task that has issued this system call.) [Assembler format] [Large/Small model] MOV CALLT [C format] ext_tsk (); bnk0_b, #1 [40H]
32
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.1.3 ter_tsk (Terminate Task)
[Function] Forcibly aborts another task. [Remarks] This system call forcibly aborts the task specified by tskid. If the specified task is placed in a queue, the task is released from the queue when the "ter_tsk" system call has been issued. Therefore, the task is released from the wait state before it is terminated. "ter_tsk" does not automatically release the resources that the task has acquired before. resources before terminating the task. This system call cannot specify the task itself that issues it. [System call ID number] ter_tsk = 2 [Parameter] tskid (Task Identifier) Task ID (TCB top address) - 24 bits (large model) - 16 bits (small model) [Return parameter] E_OK E_DMT [Assembler format] [Large model] MOV MOVW MOV CALLT bnk0_b, #2 bnk0_up, #tskid bnk0_d, #tskid [40H] : C register = return parameter [C format] ret = ter_tsk(tskid); char *tskid; [Small model] MOV MOVW CALLT bnk0_b, #2 bnk0_up, #tskid [40H] : C register = return parameter Normal termination Specified task is in DORMANT state Release the
33
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.1.4 chg_pri (Change Task Priority) ichg_pri (Change Task Priority for Interrupt)
[Function] Changes the priority of a task. [Remarks] Changes the priority of the current task indicated by tskid to a value indicated by tskpri. The own task is specified at tskid = 0. However, the own task cannot be specified with ichg_pri. Priorities modified in the current system call are valid until remodified or performing the task is finished. The priority for a task which has been restarted is the initial priority. [System call ID number] chg_pri = 3 [Parameter] tskid (Task Identifier) tskpri(Task Priority) [Return parameter] E_OK E_DMT [Assembler format]
* On issuing chg_pri
Task ID (TCB top address) Task priority
- 24 bits (large model) - 16 bits (small model) - 8 bits
Normal termination Specified task is in DORMANT state
[Large model] MOV MOV MOVW MOV CALLT bnk0_b, #3 bnk0_e, #tskpri bnk0_up, #tskid bnk0_d, #tskid [40H] : C register = return parameter
* On issuing ichg_pri
[Small model] MOV MOV MOVW CALLT bnk0_b, #3 bnk0_e, #tskpri bnk0_up, #tskid [40H] : C register = return parameter
[Large model] MOV MOVG CALLT E, #tskpri UUP, #tskid [42H] : C register = return parameter [C format]
* On issuing chg-pri
[Small model] MOV MOVW CALLT E, #tskpri UP, #tskid [42H] : C register = return parameter
* On issuing ichg-pri
ret = chg_pri (tskid, tskpri); char char *tskid; tskpri;
ret = ichg_pri (tskid, tskpri); char char *tskid; tskpri;
34
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.1.5 rot_rdq (Rotate Ready Queue) irot_rdq (Rotate Ready Queue for Interrupt)
[Function] Rotates the ready queue of the specified priority. [Remarks] Rotates the ready queue of the priority indicated by tskpri. Consequently, the task placed at the top of the ready queue is placed at the end of the queue and execution of the task of the same priority is changed. When tskpri = 0, the ready queue of the priority of the task itself is rotated. Therefore, this system call can be issued to relinquish execution privileges so that the task itself is placed at the end of the ready queue. However, irot_rdq cannot specify tskpri = 0. If no task exists in the ready queue of the specified priority, nothing is executed, but this does not result in an error. [System call ID number] rot_rdq = 4 [Parameter] tskpri (Task Priority) [Return parameter] E_OK [Assembler format]
* On issuing rot_rdq
Task priority
- 8 bits
Normal termination
[Large/Small model] MOV MOV CALLT bnk0_v, #4 bnk0_e, #tskpri [40H] : C register = return parameter
* On issuing irot_rdq
[Large/Small model] MOV CALLT E, #tskpri [44H] : C register = return parameter [C format]
* On issuing rot_rdq * On issuing irot_rdq
ret = rot_rdq (tskpri); char tskpri;
ret = irot_rdq (tskpri); char tskpri;
35
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.1.6 tsk_sts (Get Task Status)
[Function] Gets a task's state. [Remarks] References each status of the task indicated by tskid, and sets the current priority of the target task "tskpri" and task state "tskstat" in a specified address (refer to the figure below). The own task is specified at tskid = 0. The area for P-tsksts should be allocated by the user. For the task status, refer to APPENDIX 1.
p_tsksts 1H Task priority (tskpri) 0H Task status (tskstat)
[System call ID number] tsk_sts = 5 [Parameter] tskid (Task Identifier) p_tsksts (Pointer of Task Status) Task ID (TCB top address) Address of area storing task status - 24 bits (large model) - 16 bits (small model) - 24 bits (large model) - 16 bits (small model) [Return parameter] E_OK [Assembler format] [Large model] MOV MOVW MOV MOVW MOV CALLT bnk0_b, #5 bnk0_up, #tskid bnk0_d, #tskid bnk0_vp, #p_tsksts bnk0_e, #p_tsksts [40H] : C register = return parameter [C format] ret = tsk_sts (p_tsksts,tskid); short char *p_tsksts; *tskid; [Small model] MOV MOVW MOVW CALLT bnk0_b, #5 bnk0_up, #tskid bnk0_vp, #p_tsksts [40H] : C register = return parameter Normal termination
36
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.1.7 slp_tsk (Sleep Task)
[Function] Places a task in the WAIT state. [Remarks] Places the task itself in the WAIT state from the RUN state. This WAIT state is released issuing the system call "wup_tsk (iwup_tsk)" or "ret_wup" to the task. [System call ID number] slp_tsk = 6 [Parameter] None [Return parameter] E_OK [Assembler format] [Large/Small model] MOV CALLT bnk0_b, #6 [40H] : C register = return parameter [C format] ret = slp_tsk (); Normal termination
37
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.1.8 wai_tsk (Wait for Wakeup Task)
[Function] Places a task in the WAIT state for a fixed amount of time. [Remarks] Places the task itself in the WAIT state for a fixed amount of time from the RUN state. This WAIT state can be released issuing the system call "wup_tsk (iwup_tsk)" or "ret_wup" to this task, or when the amount of time specified by tmout has elapsed. If the value of tmout is 0, immediate return is executed, and E_TMOUT is returned as the return parameter. If tmout is 0 and the number of wake-up request counts is 1 or more, E_OK is returned (and the wake-up request count is updated). When this system call is used, the vector address of the timer to be used must be set. For the timer to be used, refer to 5.1 Hardware Used. Wait time = Set interrupt time TMOUT value [System call ID number] wai_tsk = 7 [Parameter] tmout (Timeout) [Return parameter] E_OK E_TMOUT [Assembler format] [Large/Small model] MOV MOVW CALLT bnk0_b, #7 bnk0_vp, #tmout [40H] : C register = return parameter [C format] ret = wai_tsk (tmout); unsigned short tmout; Normal termination Elapsed time Time out specification - 16 bits
38
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.1.9 wup_tsk (Wakeup Task) iwup_tsk (Wakeup Task for Interrupt)
[Function] Wakes up a task and places it in the READY state from the WAIT state. [Remarks] Places a task that has been placed in the WAIT state by system call "slp_tsk" or "wai_tsk" in the READY state. The target task is indicated by tskid. The task itself cannot be specified. If the target task has not executed "slp_tsk" or "wai_tsk" and is not in the WAIT state, this "wup_tsk" request is queued. In this case, this "wup_tsk" request becomes valid when the target task later executes "slp_tsk" or "wai_tsk". If the number of wake-up requests in the queue is about to exceed the upper limit (0FFH), an error (E_QOVR) is returned. [System call ID number] wup_tsk = 8 [Parameter] tskid (Task Identifier) [Return parameter] E_OK E_DMT E_QOVR [Assembler format]
* On issuing wup_tsk
Task ID (TCB top address)
- 24 bits (large model) - 16 bits (small model)
Normal termination Specified task is in DORMANT state Queue overflow
[Large model] MOV MOVW MOV CALLT bnk0_b, #8 bnk0_up, #tskid bnk0_d, #tskid [40H] : C register = return parameter
* On issuing iwup_tsk
[Small model] MOV MOVW CALLT bnk0_b, #8 bnk0_up, #tskid [40H] : C register = return parameter
[Large model] MOVG CALLT UUP, #tskid [46H] : C register = return parameter [C format]
* On issuing wup_tsk
[Small model] MOVW CALLT UP, #tskid [46H] : C register = return parameter
* On issuing iwup_tsk
ret = wup_tsk (tskid); char *tskid;
ret = iwup_tsk (tskid); char *tskid;
39
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.1.10 can_wup (Cancel Wakeup Task)
[Function] Cancels a task wake-up request. [Remarks] Stores the number of wake-up requests queued to the target task indicated by tskid to a specified pointer, and at the same time cancels all wake-up requests. The area for p_wupcnt should be allocated by the user. The own task is specified at tskid = 0. [System call ID number] can_wup = 9 [Parameter] tskid (Task Identifier) p_wupcnt (Pointer of Wakeup Count) Task ID (TCB top address) Pointer storing the number of wake-up requests queued [Return parameter] E_OK E_DMT [Assembler format] [Large model] MOV MOVW MOV MOVW MOV CALLT bnk0_b, #9 bnk0_up, #tskid bnk0_d, #tskid bnk0_vp, #p_wupcnt bnk0_e, #p_wupcnt [40H] : C register = return parameter [C format] ret = can_wup (p_wupcnt,tskid); char char *p_wupcnt; *tskid; [Small model] MOV MOVW MOVW CALLT bnk0_b, #9 bnk0_up, #tskid bnk0_vp, #p_wupcnt [40H] : C register = return parameter Normal termination Specified task is in DORMANT state - 24 bits (large model) - 16 bits (small model) - 24 bits (large model) - 16 bits (small model)
40
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.2
Synchronization and Communication
The following system calls are used for synchronization and communication: (1) set_flg (2) iset_flg (3) clr_flg (4) wai_flg (5) cwai_flg (6) pol_flg (7) cpol_flg (8) sig_sem (9) isig_sem (10) wai_sem (11) preq_sem (12) snd_msg (13) isnd_msg (14) rcv_msg (15) prcv_msg Sets an event flag Sets an event flag (when used in interrupt handler) Clears an event flag Waits for an event flag (without clear) Waits for an event flag (with clear) Obtains an event flag (without clear) Obtains an event flag (with clear) Signal manipulation of a semaphore (V instruction) Signal manipulation of a semaphore (when used in interrupt handler) Wait manipulation of a semaphore (P instruction) Obtains the semaphore resource Sends a message Sends a message (when used in interrupt handler) Waits for message reception Receives a message
41
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.2.1 set_flg (Set Eventflag) iset_flg (Set Eventflag for Interrupt)
[Function] Sets an event flag. [Remarks] The event flag indicated by flgid is set to 1. If a task exists that has been made to wait for the event flag by "wai_flg, cwai_flg", the task is released from the WAIT state and placed in the READY state. Two or more tasks can wait for the same event flag. In this case, the tasks can be released from the WAIT state when "set_flg" is issued once. [System call ID number] set_flg = 10 [Parameter] flgid (Eventflag Identifier) Event flag ID (Eventflag top address) - 24 bits (large model) - 16 bits (small model) [Return parameter] E_OK [Assembler format]
* On issuing set_flg
Normal termination
[Large model] MOV MOVW MOV CALLT bnk0_b, #10 bnk0_up, #flgid bnk0_d, #flgid [40H] : C register = return parameter
* On issuing iset_flg
[Small model] MOV MOVW CALLT bnk0_b, #10 bnk0_up, #flgid [40H] : C register = return parameter
[Large model] MOVG CALLT UUP, #flgid [48H] : C register = return parameter [C format]
* On issuing set_flg
[Small model] MOVW CALLT UP, #flgid [48H] : C register = return parameter
* On issuing iset_flg
ret = set_flg (flgid); char *flgid;
ret = iset_flg (flgid); char *flgid;
42
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.2.2 clr_flg (Clear Eventflag)
[Function] Clears an event flag. [Remarks] Clears the event flag indicated by flgid. Even if a task exists that has been made to wait for the event flag by "wai_flg", "cwai_flg", that task is not released from the WAIT state. [System call ID number] clr_flg = 11 [Parameter] flgid (Eventflag Identifier) Event flag ID (Eventflag top address) - 24 bits (large model) - 16 bits (small model) [Return parameter] E_OK [Assembler format] [Large model] MOV MOVW MOV CALLT bnk0_b, #11 bnk0_up, #flgid bnk0_d, #flgid [40H] : C register = return parameter [C format] ret = clr_flg (flgid); char *flgid; [Small model] MOV MOVW CALLT bnk0_b, #11 bnk0_up, #flgid [40H] : C register = return parameter Normal termination
43
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.2.3 wai_flg (Wait Eventflag)
[Function] Waits for an event flag (without clear). [Remarks] Waits until an event flag indicated by flgid is set to 1. The value of the event flag remains set after it has been set and the task has been released from the WAIT state. Two or more tasks can wait for the same event flag. [System call ID number] wai_flg = 12 [Parameter] flgid (Eventflag Identifier) Event flag ID (Eventflag top address) - 24 bits (large model) - 16 bits (small model) [Return parameter] E_OK [Assembler format] [Large model] MOV MOVW MOV CALLT bnk0_b, #12 bnk0_up, #flgid bnk0_d, #flgid [40H] : C register = return parameter [C format] ret = wai_flg (flgid); char *flgid; [Small model] MOV MOVW CALLT bnk0_b, #12 bnk0_up, #flgid [40H] : C register = return parameter Normal termination
44
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.2.4 cwai_flg (Wait and Clear Eventflag)
[Function] Waits for an event flag (with clear). [Remarks] Waits until an event flag indicated by flgid is set to 1. The event flag is cleared when it has been set and the task has been released from the WAIT state. If "set_flg" is issued when two or more tasks are waiting for an event flag, the tasks are sequentially woken up starting from the one placed at the top of the queue. However, the tasks following the one in the WAIT state by "cwai_flg" cannot be woken up because the event flag is cleared. [System call ID number] cwai_flg = 13 [Parameter] flgid (Eventflag Identifier) Event flag ID (Eventflag top address) - 24 bits (large model) - 16 bits (small model) [Return parameter] E_OK [Assembler format] [Large model] MOV MOVW MOV CALLT bnk0_b, #13 bnk0_up, #flgid bnk0_d, #flgid [40H] : C register = return parameter [C format] ret = cwai_flg (flgid); char *flgid; [Small model] MOV MOVW CALLT bnk0_b, #13 bnk0_up, #flgid [40H] : C register = return parameter Normal termination
45
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.2.5 pol_flg (Poll Eventflag)
[Function] Obtains an event flag (without clear). [Remarks] Checks whether the event flag indicated by flgid is set. If the flag is set, the task is terminated normally; if not, an error is returned (E_PLFAIL). In either case, the original value of the event flag is retained. [System call ID number] pol_flg = 14 [Parameter] flgid (Eventflag Identifier) Event flag ID (Eventflag top address) - 24 bits (large model) - 16 bits (small model) [Return parameter] E_OK E_PLFAIL [Assembler format] [Large model] MOV MOVW MOV CALLT bnk0_b, #14 bnk0_up, #flgid bnk0_d, #flgid [40H] : C register = return parameter [C format] ret = pol_flg (flgid); char *flgid; [Small model] MOV MOVW CALLT bnk0_b, #14 bnk0_up, #flgid [40H] : C register = return parameter Normal termination Polling failed
46
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.2.6 cpol_flg (Poll and Clear Eventflag)
[Function] Obtains an event flag (with clear). [Remarks] Checks whether the event flag indicated by flgid is set. If the flag is set, the flag is cleared and the task is terminated normally; if not, an error is returned (E_PLFAIL) with the flag value left untouched. [System call ID number] cpol_flg = 15 [Parameter] flgid (Eventflag Identifier) Event flag ID (Eventflag top address) - 24 bits (large model) - 16 bits (small model) [Return parameter] E_OK E_PLFAIL [Assembler format] [Large model] MOV MOVW MOV CALLT bnk0_b, #15 bnk0_up, #flgid bnk0_d, #flgid [40H] : C register = return parameter [C format] ret = cpol_flg (flgid); char *flgid; [Small model] MOV MOVW CALLT bnk0_b, #15 bnk0_up, #flgid [40H] : C register = return parameter Normal termination Polling failed - 8 bits - 8 bits
47
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.2.7 sig_sem (Signal Semaphore) isig_sem (Signal Semaphore for Interrupt)
[Function] Executes signal manipulation for semaphore (V instruction). [Remarks] If tasks exist that wait for a semaphore indicated by semid, the task at the top of the queue is placed in the READY state. If no task is waiting for the semaphore, the count value of the semaphore is increased by one. If the count value of the semaphore is about to exceed the upper limit (0FFH), "E_QOVR" is returned as an error code. [System call ID number] sig_sem = 16 [Parameter] semid (Semaphore Identifier) Semaphore ID (Semaphore top address) - 24 bits (large model) - 16 bits (small model) [Return parameter] E_OK E_QOVR [Assembler format]
* On issuing sig_sem
Normal termination Queue overflow
[Large model] MOV MOVW MOV CALLT bnk0_b, #16 bnk0_up, #semid bnk0_d, #semid [40H] : C register = return parameter
* On issuing isig_sem
[Small model] MOV MOVW CALLT bnk0_b, #16 bnk0_up, #semid [40H] : C register = return parameter
[Large model] MOVG CALLT UUP, #semid [4AH] : C register = return parameter [C format]
* On issuing sig_sem
[Small model] MOVW CALLT UP, #semid [4AH] : C register = return parameter
* On issuing isig_sem
ret = sig_sem (semid); char *semid;
ret = isig_sem (semid); char *semid;
48
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.2.8 wai_sem (Wait on Semaphore)
[Function] Executes wait manipulation for a semaphore (P instruction). [Remarks] If the count value of the semaphore indicated by semid is 1 or more, the count value of the semaphore is decremented by one, and to the task that issued this system call. If the count value of the semaphore is 0, the count value of the semaphore is not changed, and the task that has issued this system call is placed in the WAIT state. [System call ID number] wai_sem = 17 [Parameter] semid (Semaphore Identifier) Semaphore ID (Semaphore top address) - 24 bits (large model) - 16 bits (small model) [Return parameter] E_OK [Assembler format] [Large model] MOV MOVW MOV CALLT bnk0_b, #17 bnk0_up, #semid bnk0_d, #semid [40H] : C register = return parameter [C format] ret = wai_sem(semid); char *semid; [Small model] MOV MOVW CALLT bnk0_b, #17 bnk0_up, #semid [40H] : C register = return parameter Normal termination
49
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.2.9 preq_sem (Poll and Request Semaphore)
[Function] Obtains a semaphore resource. [Remarks] If the count value of the semaphore indicated by semid is 1 or more, the count value of the semaphore is decremented by one, and the task terminates normally. If the count value of the semaphore is 0, the semaphore value is not changed and an error is returned (E_PLFAIL). [System call ID number] preq_sem = 18 [Parameter] semid (Semaphore Identifier) Semaphore ID (Semaphore top address) - 24 bits (large model) - 16 bits (small model) [Return parameter] E_OK E_PLFAIL [Assembler format] [Large model] MOV MOVW MOV CALLT bnk0_b, #18 bnk0_up, #semid bnk0_d, #semid [40H] : C register = return parameter [C format] ret = preq_sem(semid); char *semid; [Small model] MOV MOVW CALLT bnk0_b, #18 bnk0_up, #semid [40H] : C register = return parameter Normal termination Polling failed
50
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.2.10
snd_msg (Send Message to Mailbox) isnd_msg (Send Message to Mailbox for Interrupt)
[Function] Sends a message. [Remarks] Sends a message at the address pk_msg to a mail box indicated by mbxid. If a task exists that is waiting for the message, the top address of the sent message is returned, and the task is placed in the READY state. In this case, the message is not sent to the mail box. If there is no task waiting for the message, the task issuing "snd_msg" is not placed in the WAIT state. This system call only sends a message to a mail box, and execution of the task continues. In other words, message transmission is carried out asynchronously. The first 2 bytes of the transmitting message are used as the link area of the queue. Therefore, be sure to store the message from the 3rd byte and onward. [System call ID number] snd_msg = 19 [Parameter] mbxid (Mailbox Identifier) pk_msg (Message Packet) Mail box ID (Mailbox top address) Transmission message top address - 24 bits (large model) - 16 bits (small model) - 24 bits (large model) - 16 bits (small model) [Return parameter] E_OK [Assembler format]
* On issuing snd_msg
Normal termination
[Large model] MOV MOVW MOV MOVW MOV CALLT bnk0_b, #19 bnk0_up, #mbxid bnk0_d, #mbxid bnk0_vp, #pk_msg bnk0_e, #pk_msg [40H] : C register = return parameter
* On issuing isnd_msg
[Small model] MOV MOVW MOVW CALLT bnk0_b, #19 bnk0_up, #mbxid bnk0_vp, #pk_msg [40H] : C register = return parameter
[Large model] MOVG MOVG CALLT UUP, #mbxid VVP, #pk_msg [4CH] : C register = return parameter
[Small model] MOVW MOVW CALLT UP, #mbxid VP, #pk_msg [4CH] : C register = return parameter
51
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
[C format]
* On issuing snd_msg * On issuing isnd_msg
ret = snd_msg (mbxid, pk_msg); char char *mbxid; *pk_msg;
ret = isnd_msg (mbxid, pk_msg); char char *mbxid; *pk_msg;
52
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.2.11 rcv_msg (Receive Message from Mailbox)
[Function] Waits for reception from a mail box. [Remarks] Receives a message from a mail box indicated by mbxid and sets the top address of the received message in an address specified by the parameter. If the message has not arrived at the mail box, the task that has issued this system call is placed in the WAIT state. The area for ppk-msg should be allocated by the user. Received message becomes a top address of the message area actual data is stored. [System call ID number] rcv_msg = 20 [Parameter] mbxid (Mailbox Identifier) ppk_msg (Pointer of Message Packet) Mail box ID (Mailbox top address) Address of area storing the top address of received message [Return parameter] E_OK [Assembler format] [Large model] MOV MOVW MOV MOVG PUSH CALLT bnk0_b, #20 bnk0_up, #mbxid bnk0_d, #mbxid VVP, #ppk_msg VVP [40H] : C register = return parameter [C format] ret = rcv_msg (ppk_msg,mbxid); char char **ppk_msg; *mbxid; [Small model] MOV MOVW MOVW PUSH CALLT bnk0_b, #20 bnk0_up, #mbxid AX, #ppk_msg AX [40H] : C register = return parameter Normal termination - 24 bits (large model) - 16 bits (small model) - 24 bits (large model) - 16 bits (small model)
53
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.2.12 prcv_msg (Poll and Receive Message from Mailbox)
[Function] Receives a message. [Remarks] If a message has arrived to the mail box indicated by mbxid, it receives the message and sets the top address of the received message in an address specified by the parameter. In this case, this system call terminates normally. If the message has not arrived to the mail box, this system call returns "E_PLFAIL" as an error code. The area for ppk-msg should be allocated by the user. Received message becomes a top address of the message area actual data is stored. [System call ID number] prcv_msg = 21 [Parameter] mbxid (Mailbox Identifier) ppk_msg (Pointer of Message Packet) Mail box ID (Mailbox top address) Address of area storing the top address of received message [Return parameter] E_OK E_PLFAIL [Assembler format] [Large model] MOV MOVW MOV MOVW MOV CALLT bnk0_b, #21 bnk0_up, #mbxid bnk0_d, #mbxid bnk0_vp, #ppk_msg bnk0_e, #ppk_msg [40H] : C register = return parameter [C format] ret = prcv_msg (ppk_msg,mbxid); char char **ppk_msg; *mbxid; [Small model] MOV MOVW MOVW CALLT bnk0_b, #21 bnk0_up, #mbxid bnk0_vp, #ppk_msg [40H] : C register = return parameter Normal termination Polling failed - 24 bits (large model) - 16 bits (small model) - 24 bits (large model) - 16 bits (small model)
54
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.3
Memory Management
The following system calls are related to memory: (1) pget_blk (2) rel_blk Gets a fixed-length memory block Releases a fixed-length memory block
55
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.3.1 pget_blk (Poll and Get Fixed-Length Memory Block)
[Function] Gets a memory block of a fixed length. [Remarks] Gets a memory block of a fixed length from a memory pool indicated by mplid. This memory block can be used as a message area for communication between tasks. The size of the memory block is determined on creation of the system and is fixed. When a memory block can be gotten, the top address of the memory block is set in an address specified by the parameter. The area for p-blk should be allocated by the user. [System call ID number] pget_blk = 22 [Parameter] mplid (Memory Pool Identifier) p_blk (Pointer of Block Start Address) Memory pool ID (Memory pool top address) Address of area storing the top address of the memory block [Return parameter] E_OK E_PLFAIL [Assembler format] [Large model] MOV MOVW MOV MOVW MOV CALLT bnk0_b, #22 bnk0_up, #mplid bnk0_d, #mplid bnk0_vp, #p_blk bnk0_e, #p_blk [40H] : C register = return parameter [C format] ret = pget_blk (p_blk,mplid); char char **p_blk; *mplid; [Small model] MOV MOVW MOVW CALLT bnk0_b, #22 bnk0_up, #mplid bnk0_vp, #p_blk [40H] : C register = return parameter Normal termination Polling failed - 24 bits (large model) - 16 bits (small model) - 24 bits (large model) - 16 bits (small model) If the memory block cannot be gotten, an error code "E_PLFAIL" is returned. In either case, the task is not placed in the WAIT state.
56
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.3.2 rel_blk (Release Fixed-Length Memory Block)
[Function] Releases a memory block of a fixed length. [Remarks] Releases the memory block indicated by blk to a memory pool specified by mplid. [System call ID number] rel_blk = 23 [Parameter] mplid (Memory Pool Identifier) blk (Block Start Address) Memory pool ID (Memory pool top address) Top address of the memory block - 24 bits (large model) - 16 bits (small model) - 24 bits (large model) - 16 bits (small model) [Return parameter] E_OK [Assembler format] [Large model] MOV MOVW MOV MOVW MOV CALLT bnk0_b, #23 bnk0_up, #mplid bnk0_d, #mplid bnk0_vp, #blk bnk0_e, #blk [40H] : C register = return parameter [C format] ret = rel_blk (mplid,blk); char char *mplid; *blk; [Small model] MOV MOVW MOVW CALLT bnk0_b, #23 bnk0_up, #mplid bnk0_vp, #blk [40H] : C register = return parameter Normal termination
57
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.4
Interrupt Processing
The following system calls can be used for interrupt processing: (1) ret_int (2) ret_wup Terminates the interrupt handler Returns from an interrupt and wakes up a task
58
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.4.1 ret_int (Return from Interrupt Handler)
[Function] Returns from an interrupt handler. [Remarks] This system call is issued when execution is returned from an interrupt handler. Even if "i_yyy" system call is issued in the interrupt handler, dispatching does not take place and is delayed until execution exits from the interrupt handler after this system call has been issued. [System call ID number] None [Parameter] None [Return parameter] None. Does not return to the interrupt handler that issued the system call. [Assembler format] [Large/Small model] BR !ret_int
Unlike the other system calls, this system call is caused to branch by the jump instruction. Caution When this system call is issued from an interrupt handler, be sure to save the register values before the interrupt occured to the stack. Save the register values to the stack in the sequence shown in Fig. 4-2. If the interrupt handler occupies a register bank, select the register bank of the task executed before the interrupt has occurred, and then call this system call. [C format] ret_int (); Remark Because this system call is only supported in version 2.00 or above of the C complier CC78K4, it cannot be used with a C complier of a version lower than 2.00. With a C complier of a version 2.00 or above, specify "#pragmaDrtos_interrupt" (refer to APPENDIX 2).
59
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.4.2 ret_wup (Return and Wakeup Task)
[Function] Returns from an interrupt handler and wakes up a task. [Remarks] Returns from an interrupt handler and wakes up an interrupt processing task indicated by tskid (the task placed in the WAIT state by "slp_tsk" or "wai_tsk"). If the target task does not execute "slp_tsk" or "wai_tsk", the request is queued. Even if "i_yyy" system call is issued in the interrupt handler, dispatching does not take place and is delayed until execution exits from the interrupt handler after this system call has been issued. [System call ID number] None [Parameter] tskid (Task Identifier) Task ID (TCB top address) - 24 bits (large model) - 16 bits (small model) [Return parameter] None. Does not return to the interrupt handler that issued the system call. [Assembler format] [Large/Small model] MOVG BR UUP, #tskid !ret_wup
Unlike the other system calls, this system call is caused to branch by the jump instruction. Caution When this system call is issued from an interrupt handler, be sure to save the register values before the interrupt occured to the stack. Save the register values to the stack in the sequence shown in Fig. 4-2. If the interrupt handler occupies a register bank, select the register bank of the task executed before the interrupt has occurred, and then call this system call. [C format] ret_wup (tskid); char Remark *tskid; Because this system call is only supported in version 2.00 or above of the C complier CC78K4, it cannot be used with a C complier of a version lower than 2.00. With a C complier of a version 2.00 or above, specify "#pragmaDrtos_interrupt" (refer to APPENDIX 2).
60
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
Fig. 4-2 Stack Status When ret_int and ret_wup Are Called
When large model is used High address +17H +16H +15H +14H +13H +12H +11H +10H +0FH +0EH +0DH +0CH +0BH +0AH + 9H + 8H + 7H + 6H + 5H + 4H + 3H + 2H + 1H PC19-16 PSWL PC15-8 PC7-0 W H(R15) L(R14) T D(R13) E(R12) U R11 R10 V R9 R8 R7 R6 R5 R4 B(R3) C(R2) A(R1) X(R0) Low address PC19-16 PSWL PC15-8 PC7-0 H(R15) L(R14) D(R13) E(R12) R11 R10 R9 R8 R7 R6 R5 R4 B(R3) C(R2) A(R1) X(R0) Low address PSWH7-4 PSWH7-4 Automatically saved by hardware High address +13H +12H +11H +10H +0FH +0EH +0DH +0CH +0BH +0AH + 9H + 8H + 7H + 6H + 5H + 4H + 3H + 2H + 1H When small model is used
61
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.5
Version Management
The following system call can be used for version management: (1) get_ver Gets the version number of RX78K/IV
62
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.5.1 get_ver (Get Version No.)
[Function] Gets the version number of RX78K/IV. [Remarks] Sets the top address of the version management block in an address specified by the parameter. The version management block stores the following information. The area for pk_ver should be allocated by the user. The details of the version information is shown below.
Parameter maker id spver prver prno cpu var Size 2 byte 2 byte 2 byte 2 byte 2 byte
*4
Value 0000d 00 05201 00120 00 00d14 00 Manufacturer (NEC)
Meaning
Model number (Large model) TRON specification version (mITRON Ver. 2.01) Product version (RX78K/IV Ver. 1.20) Product management information CPU information (NEC 78K/IV series) Variation descriptor
2 byte 2 byte
[System call ID number] get_ver = 25 [Parameter] pk_ver (Packet of Version Numbers) Address of area storing the pointer to version management block - 24 bits (large model) - 16 bits (small model) [Return parameter] E_OK [Assembler format] [Large model] MOV MOVW MOV CALLT bnk0_b, #25 bnk0_vp, #pk_ver bnk0_e, #pk_ver [40H] : C register = return parameter [C format] ret = get_ver (pk_ver); char **pk_ver; [Small model] MOV MOVW CALLT bnk0_b, #25 bnk0_vp, #pk_ver [40H] : C register = return parameter Normal termination
63
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.6
Time Management
The system calls for time management are as follows: (1) act_cyc iact_cyc Controls activation of a cyclic handler. Controls activation of a cyclic handler. (When used within an interrupt handler)
64
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
4.6.1 act_cyc (Activate Cyclic Handler) iact_cyc (Activate Cyclic Handler for Interrupt)
[Function] Controls activation of a cyclic handler. [Remarks] Changes the activation state of the cyclic handler shown by cyhid to the state specified by the cyhact. The specific method of specifying cyhact is as follows:
7 0 6 0 5 0 4 0 3 0 2 0 0 : TCY_OFF (Not started) 1 : TCY_ON (started) Fixed to 0 1 : TCY_INI (Initializes the cycle time) 1 0 bit
cyhact = (TCY_OFF || TCY_ON) | [TCY_INI] "cyhact = TCY_OFF" means that the cyclic handler has temporarily stopped. During this time, the handler is not started. "cyhact = TCY_ON" sets the activation state to ON, independently of the elapsing of the cycle. The specified cycles are counted even while the activation state is OFF; therefore, the time from execution of the "act_cyc (iact_cyc)" system call until the first execution of the cyclic handler is not constant. "cyhact = (TCY_ON | TCY_INI)" not only sets the activation state to ON but at the same time clears the cyclic handler counter. Therefore, the initial handler startup takes place exactly after the specified number of cycles has elapsed since the "actcyc (iact_cyc)" system call. A cyclic handler cannot be created or destroyed dynamically. configurator. [System call ID number] act_cyc = 26 [Parameter] cyhid (Cyclic Handler Identifier) cyhact (Cyclic Handler Activation) [Return parameter] E_OK Normal termination Cyclic handler ID (HCB top address) Cyclic handler activation state - 24 bits (large model) - 16 bits (small model) - 8 bits A cycle handler is registered with the
65
CHAPTER 4
RX78K/IV SYSTEM CALL LIST
[Assembler format]
* In the case of act_cyc:
[Large model] MOV MOV MOVW MOV CALLT bnk0_b, #26 bnk0_e, #cyhact bnk0_up, #cyhid bnk0_d, #tskpri [40H] : C register = return parameter
* In the case of iact_cyc:
[Small model] MOV MOV MOVW CALLT bnk0_b, #26 bnk0_e, #cyhact bnk0_up, #cyhid [40H] : C register = return parameter
[Large model] MOV MOVG CALLT E, #cyhact UUP, #cyhid [4EH] : C register = return parameter [C format]
* In the case of act_cyc:
[Small model] MOV MOVW CALLT E, #cyhact UP, #cyhid [4EH] : C register = return parameter
* In the case of iact_cyc:
ret = act_cyc(cyhid, cyhact); char char cyhid; cyhact;
ret = iact_cyc(cyhid, cyhact); char char cyhid; cyhact;
66
CHAPTER 5
RX78K/IV RESET OPERATION
A system running RX78K/IV is initialized when the system initialization reset routine stored with RX78K/IV in the internal ROM or external memory of the 78K/IV series is expected. After resetting the device, the system is branched out to the address which is set in address 0000H. Therefore, be sure to set the address of the user's initialization routine. Make sure that the user initial routine performs necessary processing such as initialization of the peripheral hardware. After this, read out the location address of the kernel from the initialization information table created by the configurator, and branch to the reset routine for system initialization. At this time, set the top address of the initialization information table to the TDE register. Fig. 5-1 shows an example program to branch to the reset routine for system initialization. The reset routine for system initialization initializes the reserved area and object in accordance with the initialization information table. After initialization, control is passed to the RX78K/IV dispatcher. The dispatcher selects a task from a ready queue initialized by the reset routine and places the task in the RUN state. The task selected at this time is called an initial task. Fig. 5-1 Reset Routine Branch Program for System Initialization (Large model)
NAME ; EXTRN ; VCTTB10 CSEG DW VCTTBL1 CSEG DW RESRTN RES_RTN: CSEG
RES_PROG SYS_INF, AT 0000H RES_RTN AT 0018H ?TMDSP ; sets vector address for timer processing ; sets vector address at reset ; initialization information table
LOCATION 0FH (Initialization of RAM, initialization of peripheral hardware, etc.) MOVG MOVW BR ; END TDE, #SYS_INF AX, [TDE] AX ; sets top address of the initialization information table to TDEreg. ; sets kernel location address to AXreg. ; branches to the reset routine for system initialization of RX78K/IV
67
CHAPTER 5
RX78K/IV RESET OPERATION
5.1
Hardware Used
With RX78K/IV, hardware such as the timer/counter unit used for "wai_tsk", "act_cyc(iact_cyc)" is used (refer to Table 5-1). Since RX78K/IV does not initialize the timer/counter unit, initialize the unit within the user initialization routine. When "wai_tsk", "act_cyc(iact_cyc)" is not used, the following timer/counter unit is not used. Table 5-1 Timer of Each CPU
CPU Timer TM3 (16 bits/timer 3) Compare Register CR30 Interrupt Vector INTC30
mPD784021, 784025 mPD784026, 78P4026
To use a timer other than TM3, set the start address ("?tmdsp") of the timer dispatcher to the vector table address of the timer used (refer to Fig. 5-1). When setting 3 for the interrupt level of the timer processing to permit multiple interrupt with the interrupt handler, this OS cannot warrant proper operations. Therefore, ensure either to set a value other than 3 for the interrupt level of the timer processing or inhibit multiple interrupt if interrupt level 3 is to be set.
68
APPENDIX 1
ERROR CODE LIST AND TASK STATUS LIST
*
Error code list
Value (8 bits, char type) 0 1 2 Normal termination Specified task is not in DORMANT state when system call "sta_tsk" is issued Specified task is in DORMANT state when system call "wup_tsk(iwup_tsk)", "ter_tsk", or "chg_pri" is issued Queue overflow When task is terminated after lapse of specified time when system call "wai_tsk" is issued Polling has failed
Error code E_OK E_NODMT E_DMT
Contents
E_QOVR E_TMOUT
3 4
E_PLFAIL
5
*
Task status list
Value 0x0 0x1 0x2 0x3 0x4 0x5 0x6 0x7 DORMANT status RUN or READY status WAIT status (timeout) WAIT status (sleep) WAIT status (eventflag) w/clear WAIT status (eventflag) w/o clear WAIT status (semaphore) WAIT status (message) Status
69
[MEMO]
70
APPENDIX 2
DESCRIPTION IN C LANGUAGE
C Compiler CC78K4 of version 2.00 or above supports tasks and interrupt handlers. Examples of describing a task and an interrupt handler in the C language are shown below.
* Task
Description format #pragma rtos_task [task function name] Example #pragma rtos_task sample extern void slp_tsk (void); void sample() { slp_tsk(); ext_tsk(); } Remark No external reference declaration is necessary for the "ext_tsk" system call. /* External reference of slp_tsk */
* Interrupt handler
Description format #pragma rtos_interrupt [(interrupt request name)(interrupt handler name){stack selection specification] Remark stack selection specification: sp = array name [ooffset position] Example #pragma rtos_interrupt INTPO sample_h sp=int_stacko10 unsigned char int_stack[10]; extern char iset_flg(char*); extern char flag_idl; sample_h() { iset_flg(&flag_idl); ret_int(); } Remark External reference declaration is not necessary for system calls "ret_int" and "ret_wup". For details, refer to the User's Manual of the C Compiler. /* Allocates stack area for interrupt */ /* External reference declaration of iset_flg */ /* External reference declaration of event flag ID */
71
[MEMO]
72
APPENDIX 3
SYSTEM CALL LIST
System Call sta_tsk ext_tsk ter_tsk chg_pri ichg_pri rot_rdq irot_rdq tsk_sts slp_tsk wai_tsk wup_tsk iwup_tsk
Function Starts task by placing it in RUN state from DORMANT state Normally terminates task itself by placing it in DORMANT state from RUN state Forcibly terminates another task by placing it DORMANT state Changes a task's priority Changes a task's priority [Issues from interrupt handler] Rotates the ready queue of the specified priority Rotates the ready queue of the specified priority [Issues from interrupt handler] Checks the task status Places the task in the WAIT state Places the task in the WAIT state temporarily Wakes up and places the task in the READY state from the WAIT state Wakes up and places the task in the READY state from the WAIT state [Issues from interrupt handler] Cancels a task wake-up request Sets an event flag Sets an event flag [Issues from interrupt handler] Clears an event flag Waits for an event flag to be set (w/o clear) Waits for an event flag to be set (w/clear) Gets an event flag (w/o clear) Gets an event flag (w/clear) Signal manipulation of a semaphore (V instruction) Signal manipulation of a semaphore (V instruction) [Issues from interrupt handler] Wait manipulation of a semaphore (P instruction) Obtains semaphore resources Sends a message Sends a message [Issues from interrupt handler] Waits for reception from a mail box Receives a message Gets a fixed-length memory block Releases a fixed-length memory block Returns from an interrupt handler Returns from an interrupt handler and wakes up a task Gets the RX78K/IV version number Controls activation of a cyclic handler. Controls activation of a cyclic handler. [Issues from interrupt handler]
Entry No. 0 1 2 3
4
5 6 7 8
9 10
can_wup set_flg iset_flg clr_flg wai_flg cwai_flg pol_flg cpol_flg sig_sem isig_sem wai_sem preq_sem snd_msg isnd_msg rcv_msg prcv_msg pget_blk rel_blk ret_int ret_wup get_ver act_cyc iact_cyc
11 12 13 14 15 16
17 18 19
20 21 22 23
25 26
-
73
[MEMO]
74
APPENDIX 4
EXAMPLE OF CYCLIC HANDLER CODING
When creating a cyclic handler, be careful about the following points. (1) The cyclic handler can be mapped in the 1MB memory space. (Large model only) (2) The cyclic handler is invoked with the "br rg" command from the timer dispatch routine. For this reason, it is handled in the same manner as an interrupt handler; therefore, the system calls that can be issued are only the "i_" system calls. However, the "i_" system calls targeting cyclic handlers cannot be issued from a cyclic handler. (3) After ending the cyclic handler processing, be sure to return to the timer dispatch routine "?tm_ret". Please code the cyclic handler processing as follows:
public extern
[cyclic handler address] ?tm_ret
[Cyclic handler address]: [Cyclic handler processing] br !?tm_ret
(4) When switching to another register bank in the cyclic handler, return to the original register bank first before returning to the timer dispatch routine. (5) In the timer dispatch routine, the "rg7, rg6, rg5, rp1, and rp0" registers are stored on the stack when interrupted. Therefore, when using the "rg4, rp3, and rp2" registers in the cyclic handler, please restore the value to the original one when returning to the timer dispatch routine.
public extrn cyc_ptr: push sel push
cyc_ptr ?tm_ret
psw rb6 rp2
(4) (5) (5) (4) (3)
cyclic handler processing pop pop br rp2 psw !?tm_ret
75
[MEMO]
76
APPENDIX 5
ESTIMATING MEMORY CAPACITY (LARGE MODEL)
On RX78K/IV, it is possible to set an area capable of generating objects (TCB, event flag, semaphore, mail box, memory pool, and cyclic handler) in an arbitrary area. However, the area of 20 bytes starting from the start address of the user-set area is an OS management area. Each object management area is secured from there on. Then the 12 bytes to 64 bytes ready queue area is secured. The ready queue area varies depending on the specified number of task priorities. Each object can be generated in up to 255 units. Calculation of the object size (data) for a system running RX78K/IV is shown below. Example Where number of objects to be created is: Task Semaphore Memory pool : 20 :4 Event flag Mail box :5 :3
Cyclic handler : 2 : 2 (number of memory blocks: 5, size of 1 memory block: 16 bytes) (number of memory blocks:10, size of 1 memory block: 32 bytes) The task priority can be used up to 10 levels. The top address (?objhead) of the OS management area shall be 0FF700H.
OS management table p = 20 o
RAM size used p 228 (bytes)
Ready queue p 4 u 10 o
TCB p 10 u 10 o
Event flag p 4u5 o
Semaphore p 4u4 o
Mail box p 4u3 o
Cyclic handler p 10 u 2
RAM size used p 408 (bytes) Total = 4 o 16 u 5
Memory pool p o 4 o 32 u 10 228 o 408 = 636 (bytes)
77
APPENDIX 5
ESTIMATING MEMORY CAPACITY (LARGE MODEL)
0FFEFFH Stack area per each task
0FF97CH Ready queue 0FF954H Memory pool 0FF7BCH Mail box 0FF7B0H Semaphore 0FF7A0H Event flag 0FF78CH Cyclic handler 0FF778H TCB area 0FF714H OS management table 20 bytes 10 bytes*10 10 bytes*2 4 bytes*5 4 bytes*4 16 bytes* 5+4 bytes 32 bytes*10+4 bytes 4 bytes*10
4 bytes*3
(?objhead) 0FF700H
78
APPENDIX 6
ESTIMATING MEMORY CAPACITY (SMALL MODEL)
On RX78K/IV, it is possible to set an area capable of generating objects (TCB, event flag, semaphore, mail box, memory pool, and cyclic handler) in 256 bytes of the internal RAM area 0F700H through 0F7FFH. However, the area of 14 bytes starting from 0F700H is an OS management area. Each object management area is secured from there on. Then the 6 bytes to 32 bytes ready queue area is secured. The ready queue area varies depending on the specified number of task priorities. Each object can be generated in up to 255 units. Calculation of the object size (data) for a system running RX78K/IV is shown below. Example Where number of objects to be created is: Task Semaphore Memory pool : 20 :4 Event flag Mail box :5 :3
Cyclic handler : 2 : 2 (number of memory blocks: 5, size of 1 memory block: 10 bytes) (number of memory blocks: 10, size of 1 memory block: 6 bytes) The task priority can be used up to 10 levels. The top address (?objhead) of the OS management area shall be 0F700H.
OS management table p = 14 o
RAM size used p 154 (bytes)
Ready queue p 2 u 10 o
TCB p 8 u 10 o
Event flag p 2u5 o
Semaphore p 2u4 o
Mail box p 2u3 o
Cyclic handler p 8u2
RAM size used p 94 (bytes) Total = 2 o 10 u 3
Memory pool p o 2 o 6 u 10 154 o 94 = 248 (bytes)
79
APPENDIX 6
ESTIMATING MEMORY CAPACITY (SMALL MODEL)
0FEFFH
Stack area per each task
0F7F8H Ready queue 0F7E4H Memory pool 0F786H Mail box 0F780H Semaphore 0F778H Event flag 0F76EH Cyclic handler 0F75EH TCB area 0F70EH OS management table 14 bytes 8 bytes*10 8 bytes*2 2 bytes*5 2 bytes*4 10 bytes* 3+2 bytes 6 bytes*10+2 bytes 2 bytes*10
2 bytes*3
(?objhead) 0F700H
80
APPENDIX 7
STANDBY FUNCTION
The RX78K/IV places the CPU in the HALT status as default assumption when there are no longer any selected tasks. In some systems, however, the STOP mode or IDLE mode may be preferred to the HALT mode. With the RX78K/IV, therefore, the standby processing is decided by the user. The supplied sample of the standby block, "nuc_idle.asm", is shown below. Sample "nuc_idle.asm"
public @nuc_idl: mov and shr mov movw addw br ; hlt_tbl: ei mov ret ; nop nop ; ei mov ret ; nop nop ; ei mov ret ; nop nop ; ei mov ret ; end stbc, #00110001b ; set halt mode (fxx/16) stbc, #00100001b ; set halt mode (fxx/8) stbc, #00010001b ; set halt mode (fxx/4) stbc, #00000001b ; set halt mode (fxx/2) x, stbc x, #0f0h x, 1 a, #0 bc, #hlt_tbl bc, ax bc @nuc_idl cseg base
Remark
The above is the file supplied as a sample. This file is a routine that can be executed by the RX78K/IV even if the internal system clock is changed in the user system.
81
APPENDIX 7
STANDBY FUNCTION
The following sample indicates an example of changing the internal system clock if the clock is fixed in the user system. Sample 1
public @nuc_idl: ei mov ret ; end stbc, #00000001b ; set halt mode (fxx/2) @nuc_idl cseg base
Remark
The above sample is for when the internal system clock is fixed. However, do not change symbol name "@nuc_idl".
The default standby mode of the RX78K/IV is HALT. To change the mode, refer to the following:
*
To change from HALT mode to STOP mode Change standby control register (STBC) value Before change mov stbc, #00000001b o After change mov stbc, #00000010b
*
To change from HALT mode to IDLE mode Change standby control register (STBC) value Before change mov stbc, #00000001b o After change mov stbc, #00000011b
For the standby control register (STBC), refer to the User's Manual of the device.
82
APPENDIX 8
MAXIMUM STACK SIZE USED BY EACH SYSTEM CALL
The stack area of the task that has issued the system call is used as a stack area used for system call processing. Therefore, the stack size of each system call must be determined taking into consideration the stack size used for the user task and the maximum stack size of the system call. The stack area which is used for the interrupt handler and the timer processing can be set to an arbitrary address. However, when an interrupt occurs, this task stack area uses 4 bytes. The maximum stack size for the processing of each system call when the program is described in assembly language is as shown in the following table.
83
APPENDIX 8
MAXIMUM STACK SIZE USED BY EACH SYSTEM CALL
Maximum Stack Size Used (Bytes) Large model System Call Name Register Bank Used 1 sta_tsk ext_tsk ter_tsk chg_pri ichg_pri rot_rdq irot_rdq tsk_sts slp_tsk wai_tsk wup_tsk iwup_tsk can_wup set_flg iset_flg clr_flg wai_flg cwai_flg pol_flg cpol_flg sig_sem isig_sem wai_sem preq_sem snd_msg isnd_msg rcv_msg prcv_msg pget_blk rel_blk ret_int ret_wup get_ver act_cyc iact_cyc Timer processing 28 28 28 28 22 28 19 28 28 28 28 18 28 28 23 28 28 28 28 28 28 21 28 28 28 23 31 28 28 28 24 24 28 28 10 24 2 to 7 8 8 8 8 22 8 19 8 8 8 8 18 8 8 23 8 8 8 8 8 8 21 8 8 8 23 11 8 8 8 24 24 8 8 10 17 1 24 24 24 24 19 24 14 24 24 24 24 16 24 24 17 24 24 24 24 24 24 16 24 24 24 20 26 24 24 24 20 20 24 24 9 20 Register Bank Used 2 to 7 8 8 8 8 19 8 14 8 8 8 8 16 8 8 17 8 8 8 8 8 8 16 8 8 8 20 10 8 8 8 20 20 8 8 9 14 Small model
Remark
Including 4 bytes (PC, PSW) used at interrupting.
84
APPENDIX 9
RESTRICTIONS ON SYMBOL NAMES
RX78K/IV uses the following symbols as public symbols. Therefore, make sure that the same names are not used on tasks and interrupt handlers. ?objhead brproc ?sysrt ?qin ?qin1 ?qout ?qout1 ?canc1 ?cnsav ?itdsp ?tmdsp ?tkdsp ?tm_ret x_serial bittbl ent_tbl sys_inf rdyqtp az_arg wtcbh wtcbt runtcb timnst wqlnkp retdata pribit cnftblp tranos bittbl end_intsys ?db_tkds end_itdsp ?db_itds @nuc_idl System call names
85
[MEMO]
86


▲Up To Search▲   

 
Price & Availability of RX78K4

All Rights Reserved © IC-ON-LINE 2003 - 2022  
[Add Bookmark] [Contact Us] [Link exchange] [Privacy policy]
Mirror Sites :  [www.datasheet.hk]   [www.maxim4u.com]  [www.ic-on-line.cn] [www.ic-on-line.com] [www.ic-on-line.net] [www.alldatasheet.com.cn] [www.gdcy.com]  [www.gdcy.net]
 . . . . .
  We use cookies to deliver the best possible web experience and assist with our advertising efforts. By continuing to use this site, you consent to the use of cookies. For more information on cookies, please take a look at our Privacy Policy. X