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CHAPTER 3 INTERRUPTS
3.6
Software Interrupts
In response to execution of a special instruction, control is transferred from the
program currently executed by the CPU to the interrupt processing program defined by
the user. This is called the software interrupt function. A software interrupt occurs
always when the software interrupt instruction is executed.
■
Software Interrupts
The CPU performs the following processing when a software interrupt occurs:
•
Saves the values in the PC, PS, AH, AL, PCB, DTB, ADB, and DPR registers of the CPU to the system
stack.
•
Sets I in the PS register. Interrupts are automatically disabled.
•
Fetches the corresponding interrupt vector value, then branches to the processing indicated by that
value.
A software interrupt request issued by the INT instruction has no interrupt request or enable flag. A
software interrupt request is always issued by executing the INT instruction.
The INT instruction does not have an interrupt level. Therefore, the INT instruction does not update ILM.
The INT instruction clears the I flag to suspend subsequent interrupt requests.
■
Structure of Software Interrupts
Software interrupts are handled within the CPU:
CPU.....Microcode: Interrupt processing step
■
List of Interrupt Vectors
"Table D-1 Interrupt Vectors" in APPENDIX D lists the interrupt vectors of the MB90360 series.
Software interrupts share the same interrupt vector area with hardware interrupts.
For example, interrupt request number INT 12 is used for external interrupt #0 to #7 of a hardware interrupt
as well as for INT #12 of a software interrupt. Therefore, external interrupt #0 and INT #12 call the same
interrupt processing routine.
■
Software Interrupt Operation
When the CPU fetches and executes the software interrupt instruction, the software interrupt processing
microcode is activated. The software interrupt processing microcode saves 12 bytes (PS, PC, PCB, DTB,
ADB, DPR, and A) to the memory area indicated by SSB and SSP. The microcode then fetches 3 bytes of
interrupt vector and loads them onto PC and PCB, resets the I flag, and sets the S flag. Then, the microcode
performs branch processing. As a result, the interrupt processing program defined by the user application
program is executed next.
Figure 3.6-1 illustrates the flow from the occurrence of a software interrupt until there is no interrupt
request in the interrupt processing program.
Содержание F2MCTM-16LX
Страница 2: ......
Страница 3: ...FUJITSU LIMITED F2MCTM 16LX 16 BIT MICROCONTROLLER MB90360 Series HARDWARE MANUAL ...
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Страница 42: ...26 CHAPTER 1 OVERVIEW ...
Страница 66: ...50 CHAPTER 2 CPU MOV ILM imm8 The instruction is executed normally but the prefix affects the next instruction ...
Страница 70: ...54 CHAPTER 2 CPU ...
Страница 134: ...118 CHAPTER 6 CLOCK SUPERVISOR ...
Страница 176: ...160 CHAPTER 8 LOW POWER CONSUMPTION MODE ...
Страница 194: ...178 CHAPTER 10 I O PORTS ...
Страница 252: ...236 CHAPTER 13 16 Bit I O TIMER ...
Страница 282: ...266 CHAPTER 14 16 BIT RELOAD TIMER ...
Страница 295: ...279 CHAPTER 15 WATCH TIMER ORG 00FFDCH Reset vector set DSL START DB 00H Set to single chip mode VECT ENDS END START ...
Страница 296: ...280 CHAPTER 15 WATCH TIMER ...
Страница 386: ...370 CHAPTER 18 8 10 BIT A D CONVERTER ...
Страница 426: ...410 CHAPTER 20 LIN UART Figure 20 5 2 ORE Flag Set Timing RDRF ORE Reception data ...
Страница 540: ...524 CHAPTER 22 ADDRESS MATCH DETECTION FUNCTION ...
Страница 568: ...552 CHAPTER 24 512K BIT FLASH MEMORY ...
Страница 633: ...617 APPENDIX B Instructions Table B 9 3 Bit Operation Instruction Map first byte 6CH ...
Страница 634: ...618 APPENDIX Table B 9 4 Character String Operation Instruction Map first byte 6EH ...
Страница 635: ...619 APPENDIX B Instructions Table B 9 5 2 byte Instruction Map first byte 6FH MUL MULW DIVU A A A ...
Страница 637: ...621 APPENDIX B Instructions Table B 9 7 ea Instruction 2 first byte 71H ...
Страница 638: ...622 APPENDIX Table B 9 8 ea Instruction 3 first byte 72H ...
Страница 639: ...623 APPENDIX B Instructions Table B 9 9 ea Instruction 4 first byte 73H ...
Страница 640: ...624 APPENDIX Table B 9 10 ea Instruction 5 first byte 74H ...
Страница 641: ...625 APPENDIX B Instructions Table B 9 11 ea Instruction 6 first byte 75H ...
Страница 642: ...626 APPENDIX Table B 9 12 ea Instruction 7 first byte 76H ...
Страница 643: ...627 APPENDIX B Instructions Table B 9 13 ea Instruction 8 first byte 77H ...
Страница 644: ...628 APPENDIX Table B 9 14 ea Instruction 9 first byte 78H ...
Страница 645: ...629 APPENDIX B Instructions Table B 9 15 MOVEA RWi ea Instruction first byte 79H ...
Страница 646: ...630 APPENDIX Table B 9 16 MOV Ri ea Instruction first byte 7AH ...
Страница 647: ...631 APPENDIX B Instructions Table B 9 17 MOVW RWi ea Instruction first byte 7BH ...
Страница 648: ...632 APPENDIX Table B 9 18 MOV Ri ea Instruction first byte 7CH ...
Страница 649: ...633 APPENDIX B Instructions Table B 9 19 MOVW ea Rwi Instruction first byte 7DH ...
Страница 650: ...634 APPENDIX Table B 9 20 XCH Ri ea Instruction first byte 7EH ...
Страница 651: ...635 APPENDIX B Instructions Table B 9 21 XCHW RWi ea Instruction first byte 7FH ...
Страница 664: ...648 APPENDIX ...
Страница 665: ...649 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
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