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User’s Manual
Preliminary PPC440x5 CPU Core
instalfa.fm.
September 12, 2002
Page 557 of 589
A.3 Allocated Instruction Opcodes
Allocated instructions are provided for purposes that are outside the scope of PowerPC Book-E architecture,
and are for implementation-dependent and application-specific use, including use within auxiliary processors.
Table A-2 lists the blocks of opcodes which have been allocated by PowerPC Book-E for these purposes. In
the table, the character “u” designates a secondary opcode bit which can be set to any value. In some cases,
the decimal value of a secondary opcode is shown in parentheses after the binary value.
All of the allocated opcodes listed in the table above are available for use by auxiliary processors attached to
the PPC440x5, except for those which have already been implemented within the PPC440x5 core for certain
implementation-specific purposes. As indicated in the table above, this is the case for certain secondary
opcodes within primary opcodes 4 and 31. These opcodes are identified in Table A-5 on page 559, along with
all of the defined, preserved, and reserved-nop class opcodes which are implemented within the PPC440x5
core.
A.4 Preserved Instruction Opcodes
The preserved instruction class is provided to support backward compatibility with the PowerPC Architecture,
and/or earlier versions of the PowerPC Book-E architecture. This instruction class includes opcodes which
were defined for these previous architectures, but which are no longer defined for PowerPC Book-E.
xori
RA, RS, IM
XOR (RS) with (
16
0 || IM).
Place result in RA.
449
xoris
RA, RS, IM
XOR (RS) with (IM ||
16
0).
Place result in RA.
450
Table A-2. Allocated Opcodes
Primary
Opcode
Extended
Opcodes
PPC440x5
Usage
0
All instruction encodings (bits 6:31) except 0x00000000
(the instruction encoding of 0x00000000 is and always will be
reserved-illegal)
None
4 All instruction encodings (bits 6:31)
Various (see Table A-5 on
page 559)
19 Secondary opcodes (bits 21:30) = 0buuuuu0u11u None
31
Secondary opcodes (bits 21:30) = 0buuuuu0011u
Secondary opcodes (bits 21:30) = 0buuuuu0u110
Secondary opcode (bits 21:30) = 0b0101010110 (342)
Secondary opcode (bits 21:30) = 0b0101110110 (374)
Secondary opcode (bits 21:30) = 0b1100110110 (822)
Various (see Table A-5 on
page 559)
59 Secondary opcodes (bits 21:30) = 0buuuuu0u10u None
63
Secondary opcodes (bits 21:30) = 0buuuuu0u10u (except second-
ary opcode decimal 12, which is the fsrp defined instruction)
None
Table A-1. PPC440x5 Instruction Syntax Summary (continued)
Mnemonic Operands Function
Other Registers
Changed
Page