Filter
Top Products
Instruction Summary A-1
Appendix A. Instruction Summary
This appendix contains PPC405 instructions summarized alphabetically and by opcode.
“Instruction Set and Extended Mnemonics – Alphabetical” lists all PPC405 mnemonics, including
extended mnemonics, alphabetically. A short functional description is included for each mnemonic.
“Instructions Sorted by Opcode,” on page A-33, lists all PPC405 instructions, sorted by primary and
secondary opcodes. Extended mnemonics are not included in the opcode list.
“Instruction Formats,” on page A-41, illustrates the PPC405 instruction forms (allowed arrangements
of fields within instructions).
A.1 Instruction Set and Extended Mnemonics – Alphabetical
Table A-1 summarizes the PPC405 instruction set, including required extended mnemonics. All
mnemonics are listed alphabetically, without regard to whether the mnemonic is realized in hardware
or software. When an instruction supports multiple hardware mnemonics (for example, b, ba, bl, bla
are all forms of b), the instruction is alphabetized under the root form. The hardware instructions are
described in detail in Chapter 9, “Instruction Set,” which is also alphabetized under the root form.
Chapter 9 also describes the instruction operands and notation.
Note the following for the branch conditional mnemonic:
Bit 4 of the BO field provides a hint about the most likely outcome of a conditional branch. (See
“Branch Prediction” on page 2-26 for a detailed description of branch prediction.) Assemblers should
set BO
4
= 0 unless a specific reason exists otherwise. In the BO field values specified in the table
below, BO
4
= 0 has always been assumed. The assembler must allow the programmer to specify
branch prediction. To do this, the assembler supports a suffixes for the conditional branch
mnemonics:
+ Predict branch to be taken.
− Predict branch not to be taken.
As specific examples, bc also could be coded as bc+ or bc–, and bne also could be coded bne+ or
bne–. These alternate codings set BO
4
= 1 only if the requested prediction differs from the standard
prediction.See “Branch Prediction” on page 2-26 for more information.
Table A-1. PPC405 Instruction Syntax Summary
Mnemonic Operands Function
Other Registers
Changed Page
add RT, RA, RB Add (RA) to (RB).
Place result in RT.
9-6
add. CR[CR0]
addo XER[SO, OV]
addo. CR[CR0]
XER[SO, OV]