37
CHAPTER 3 CPU
3.2.3
Stack Pointer (USP, SSP)
The stack pointers include a user stack pointer (USP) and a system stack pointer (SSP).
Both these pointers indicate the address where saved data and return data are stored
when the PUSH instruction, the POP instruction, and the subroutine are executed.
• The higher 8 bits of the stack address are set by the user stack bank register (USB) or
the system stack bank register (SSB).
• When the stack flag (PS: CCR: S) is "0", the USP and USB register are enabled. When
the stack flag is "1", the SSP and SSB register are enabled.
■
Stack Selection
For the F
2
MC-16LX family, two types of stack pointer can be used: system stack, and user stack.
The addresses of the stack pointers are set by the stack flag of the condition code register (CCR: S) as
shown in Table 3.2-2 "Stack Address Specification".
Since the stack flag (CCR: S) is set to "1" by a reset, the system stack pointer is used after reset.
Ordinarily, the system stack pointer is used in processing the stack at the interrupt routine, and the user
stack pointer is used in processing the stack at other than an interrupt routine. When it is not necessary to
divide the stack space, use only the system stack pointer.
Table 3.2-2 Stack Address Specification
S Flag
Stack Address
Higher 8 Bits
Lower 16 Bits
0
User stack bank register (USB)
User stack pointer (USP)
1
*
System stack bank register (SSB)
System stack pointer (SSP)
*:Reset value
Note:
When an interrupt is accepted, the stack flag (CCR: S) is set and the system stack pointer is
always used.
Summary of Contents for F2MC-16LX Series
Page 2: ......
Page 3: ...FUJITSU LIMITED F2MC 16LX 16 bit Microcontroller MB90895 series Hardware Manual ...
Page 4: ......
Page 8: ...iv ...
Page 10: ...vi ...
Page 36: ...18 CHAPTER 2 HANDLING DEVICES ...
Page 176: ...158 CHAPTER 3 CPU ...
Page 224: ...206 CHAPTER 5 Timebase timer ...
Page 294: ...276 CHAPTER 8 16 bit reload timer ...
Page 366: ...348 CHAPTER 12 DTP external interrupt ...
Page 398: ...380 CHAPTER 13 8 10 bit A D converter ...
Page 446: ...428 CHAPTER 14 UART0 ...
Page 588: ...570 CHAPTER 17 Address Match Detecting Function ...
Page 626: ...608 CHAPTER 19 512 KBIT FLASH MEMORY ...
Page 676: ...658 APPENDIX Table A 9 3 Bit Operation Instruction Map first byte 6CH ...
Page 678: ...660 APPENDIX Table A 9 5 2 byte Instruction Map first byte 6FH MUL MULW DIVU A A A ...
Page 680: ...662 APPENDIX Table A 9 7 ea Instruction 2 first byte 71H ...
Page 681: ...663 APPENDIX A Instructions Table A 9 8 ea Instruction 3 first byte 72H ...
Page 682: ...664 APPENDIX Table A 9 9 ea Instruction 4 first byte 73H ...
Page 683: ...665 APPENDIX A Instructions Table A 9 10 ea Instruction 5 first byte 74H ...
Page 684: ...666 APPENDIX Table A 9 11 ea Instruction 6 first byte 75H ...
Page 685: ...667 APPENDIX A Instructions Table A 9 12 ea Instruction 7 first byte 76H ...
Page 686: ...668 APPENDIX Table A 9 13 ea Instruction 8 first byte 77H ...
Page 687: ...669 APPENDIX A Instructions Table A 9 14 ea Instruction 9 first byte 78H ...
Page 688: ...670 APPENDIX Table A 9 15 MOVEA RWi ea Instruction first byte 79H ...
Page 689: ...671 APPENDIX A Instructions Table A 9 16 MOV Ri ea Instruction first byte 7AH ...
Page 690: ...672 APPENDIX Table A 9 17 MOVW RWi ea Instruction first byte 7BH ...
Page 691: ...673 APPENDIX A Instructions Table A 9 18 MOV ea Ri Instruction first byte 7CH ...
Page 692: ...674 APPENDIX Table A 9 19 MOVW ea Rwi Instruction first byte 7DH ...
Page 693: ...675 APPENDIX A Instructions Table A 9 20 XCH Ri ea Instruction first byte 7EH ...
Page 694: ...676 APPENDIX Table A 9 21 XCHW RWi ea Instruction first byte 7FH ...
Page 710: ......