2
2-5
Ver.0.10
CPU
2.3 Control Registers
2.3.2 Condition Bit Register: CBR (CR1)
The Condition Bit Register (CBR) is created as a separate register from the PSW by extracting the
Condition bit (C) from it. The value written to the PSW C bit is reflected in this register. This register
is a read-only register (writes to this register by "MVTC" instruction are ignored).
2.3.3 Interrupt Stack Pointer: SPI (CR2)
User Stack Pointer: SPU (CR3)
The Interrupt Stack Pointer (SPI) and User Stack Pointer (SPU) hold the current address of the
stack pointer. These registers can be accessed as general-purpose register R15. In this case,
whether R15 is used as SPI or as SPU depends on the PSW's Stack Mode (SM) bit.
2.3.4 Backup PC: BPC (CR6)
The Backup PC (BPC) is a register used to save the value of the Program Counter (PC) when an
EIT occurs. Bit 31 is fixed to 0.
When an EIT occurs, the value held in the PC immediately before the EIT occurred or the value of
the next instruction is set in this register. When the "RTE" instruction is executed, the saved value
is returned from the BPC to the PC. However, the two low-order bits of the PC when thus returned
are always fixed to "00" (control always returns to word boundaries.)
SPI
SPI
SPU
SPU
0(MSB)
0(MSB)
31(LSB)
31(LSB)
CBR
0(MSB)
31(LSB)
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 C
BPC
BPC
0
31(LSB)
0(MSB)
Summary of Contents for M32170F3VFP
Page 42: ...1 1 24 Ver 0 10 OVERVIEW 1 4 Pin Layout This is a blank page ...
Page 56: ...2 2 14 Ver 0 10 This is a blank page ...
Page 88: ...3 3 32 Ver 0 10 ADDRESS SPACE 3 7 Notes on Address Space This is a blank page ...
Page 270: ...9 9 40 Ver 0 10 DMAC 9 4 Precautions about the DMAC This is a blank page ...
Page 614: ...12 12 64 Ver 0 10 This is a blank page SERIAL I O 12 9 Precautions on Using UART Mode ...
Page 756: ...17 17 10 Ver 0 10 RAM BACKUP MODE 17 4 Exiting RAM Backup Mode Wakeup This is a blank page ...
Page 762: ...18 18 6 Ver 0 10 OSCILLATION CIRCUIT 18 2 Clock Generator Circuit This is a blank page ...
Page 831: ...CHAPTER 22 CHAPTER 22 TYPICAL CHARACTERISTICS 22 1 A D Conversion Characteristics ...
Page 833: ...Appendix 1 1 Dimensional Outline Drawing APPENDIX 1 APPENDIX 1 MECHANICAL SPECIFICATIONS ...
Page 841: ...Appendix 3 1 Precautions about Noise APPENDIX 3 APPENDIX 3 PRECAUTIONS ABOUT NOISE ...