MPC562/MPC564 Compression Features
MPC561/MPC563 Reference Manual, Rev. 1.2
Freescale Semiconductor
A-3
3. Compression of one of the instruction’s halves into a vocabulary pointer and bypass of the other
half. A bypassed field is one for which non-compressed data (16-bit halfword or 32-bit word) is
placed in the compressed code. After compression is defined, the non-compressed data field is
defined in the class.
4. Bypass of the whole instruction. No compression is permitted.
Figure A-1. Instruction Compression Alternatives
A 4-bit class identifier is added to the beginning of each compressed instruction to supply class
identification during decompression. Compressed and bypass field lengths may vary. (A fully bypassed
instruction, including its 4-bit class identifier, is 36 bits.)
The compressed instruction is guaranteed to start on an even bit. Thus, four bits are needed to find the
starting location of the instruction inside a memory word. The instruction address in decompression on
mode consists of a 28-bit word address (1 Gbyte of address space) and a 4-bit instruction pointer (IP). See
.
Uncompressed Instruction
Compressed Instruction
1.
2.
3.
4.
Legend
Uncompressed or Bypassed Code
Compressed Code
Class Identifier
OR
1.
2.
3.
4.
Summary of Contents for MPC561
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Page 144: ...Signal Descriptions MPC561 MPC563 Reference Manual Rev 1 2 2 46 Freescale Semiconductor...
Page 206: ...Central Processing Unit MPC561 MPC563 Reference Manual Rev 1 2 3 62 Freescale Semiconductor...
Page 302: ...Reset MPC561 MPC563 Reference Manual Rev 1 2 7 14 Freescale Semiconductor...
Page 854: ...Time Processor Unit 3 MPC561 MPC563 Reference Manual Rev 1 2 19 24 Freescale Semiconductor...
Page 968: ...Development Support MPC561 MPC563 Reference Manual Rev 1 2 23 54 Freescale Semiconductor...
Page 1144: ...Internal Memory Map MPC561 MPC563 Reference Manual Rev 1 2 B 34 Freescale Semiconductor...
Page 1212: ...TPU3 ROM Functions MPC561 MPC563 Reference Manual Rev 1 2 D 60 Freescale Semiconductor...
Page 1216: ...Memory Access Timing MPC561 MPC563 Reference Manual Rev 1 2 E 4 Freescale Semiconductor...