AMD-K6-2E Datasheet, PDF (33/332 Pages) Advanced Micro Devices – AMD-K6™-2E Embedded Processor

22529B/0—January 2000
Preliminary Information
AMD-K6™-2E Processor Data Sheet
Instruction Buffer
On-Chip ROM
Short Decoder #1
Short Decoder #2
Long Decoder
Vector Decoder
RISC86^® Sequencer
Vector Address
4 RISC86 Operations
Figure 4. AMD-K6™-2E Processor Decode Logic
The AMD-K6-2E processor uses a combination of decoders to
convert x86 instructions into RISC86 operations. The hardware
consists of three sets of decoders—two parallel short decoders,
one long decoder, and one vector decoder.
Parallel Short Decoders. The two parallel short decoders translate
the most commonly-used x86 instructions ( moves, shifts,
branches, ALU, FPU) and the extensions to the x86 instruction
set (MMX and 3DNow! technology) into zero, one, or two
RISC86 operations each. The short decoders only operate on
x86 instructions that are up to seven bytes long. In addition, the
decoders are designed to decode up to two x86 instructions per
clock.
Chapter 2
Internal Architecture
15