Processor Users Manual

MOTOROLA Appendix A. Register Quick Reference Guide A-1
Appendix A
Register Quick Reference Guide
A0
A0
This section provides a brief guide to the core registers.
A.1 PowerPC RegistersÑUser Registers
The implements the user-level registers deÞned by the PowerPC architecture except those
required for supporting ßoating-point operations (the ßoating-point register Þle (FPRs) and
the ßoating-point status and control register (FPSCR)). User-level, PowerPC registers are
listed in Table A-1 and Table A-2. Table A-2 lists user-level special-purpose registers
(SPRs).
Table A-2 lists SPRs deÞned by the PowerPC architecture implemented on the MPC8260.
Table A-1. User-Level PowerPC Registers (Non-SPRs)
Description Name Comments Access Level Serialize Access
General-purpose
registers
GPRs The thirty-two 32-bit (GPRs) are used for source
and destination operands. See the
Programming Environments Manual for more
information.
User Ñ
Condition register CR See the Programming Environments Manual User Only mtcrf
Table A-2. User-Level PowerPC SPRs
SPR Number
Name Comments Serialize Access
Decimal SPR [5Ð9] SPR [0Ð4]
1 00000 00001 XER See the Programming
Environments Manual
Write: Full sync
Read: Sync relative to load/store operations
8 00000 01000 LR See the Programming
Environments Manual
No
9 00000 01001 CTR See the Programming
Environments Manual
No
268 01000 01100 TBL read
1
1
Extended opcode for mftb, 371 rather than 339.
See the Programming
Environments Manual
Write (as a store)
269 01000 01101 TBU read
2
2
Any write (mtspr) to this address causes an implementation-dependent software emulation exception.