41
CHAPTER 2 CPU
2.7.2
User Stack Pointer (USP) and System Stack Pointer
(SSP)
USP and SSP are 16-bit registers that indicate the memory addresses for saving and
restoring data when a push/pop instruction or subroutine is executed.
■
User Stack Pointer (USP) and System Stack Pointer (SSP)
The USP and SSP registers are used by stack instructions. The USP register is enabled when the S flag in
the processor status register is “0”, and the SSP register is enabled when the S flag is “1” (see
Figure 2.7-5 ). Since the S flag is set when an interrupt is accepted, register values are always saved in the
memory area indicated by SSP during interrupt processing. SSP is used for stack processing in an interrupt
routine, while USP is used for stack processing outside an interrupt routine. If the stack space is not
divided, use only the SSP.
During stack processing, the high-order eight bits of an address are indicated by SSB (for SSP) or USB (for
USP). USP and SSP are not initialized by a reset. Instead, they hold undefined values.
Figure 2.7-5 Stack Manipulation Instruction and Stack Pointer
Note:
Specify an even-numbered address in the stack pointer whenever possible.
AL A624
H
USB
USP
SSP
SSB
0
C6
H
56
H
F328
H
1234
H
C6F326
H
MSB
LSB
XX
XX
AL A624
H
USB
USP
SSP
SSB
0
C6
H
56
H
F326
H
1234
H
C6F326
H
24
H
A6
H
AL A624
H
USB
USP
SSP
SSB
C6
H
56
H
F328
H
1234
H
561232
H
XX
XX
1
AL A624
H
USB
USP
SSP
SSB
1
C6
H
56
H
F328
H
1232
H
561232
H
24
H
A6
H
Example of PUSHW A when S flag is "0"
Example of PUSHW A when S flag is "1"
Before execution
After execution
System stack is used because S
flag is "0".
System stack is used because
S flag is "1".
S flag
Содержание F2MCTM-16LX
Страница 2: ......
Страница 3: ...FUJITSU LIMITED F2MCTM 16LX 16 BIT MICROCONTROLLER MB90360 Series HARDWARE MANUAL ...
Страница 4: ......
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 ...
Страница 682: ......