AMD-K6-2E/400AFR AMD [Advanced Micro Devices], AMD-K6-2E/400AFR Datasheet - Page 26

• Manufacturer Part Number: AMD-K6-2E/400AFR
• Manufacturer: AMD [Advanced Micro Devices]

AMD-K6™-2E Processor Data Sheet
Enhanced RISC86
Microarchitecture
AMD-K6™-2E
Processor Block
Diagram
8
®
Th e E n h an ce d R I SC 8 6 mi c ro a rch i t e c t ure d ef i ne s t h e
characteristics of the AMD-K6-2E processor. The innovative
RISC86 microarchitecture approach implements the x86
instruction set by internally translating x86 instructions into
RISC86 operations. These RISC86 operations were specially
designed to include direct support for the x86 instruction set
while observing the RISC performance principles of fixed
length encoding, regularized instruction fields, and a large
register set.
Th e Enh a n c e d R I S C8 6 m ic ro arch i t e c t u re u s e d i n t h e
A M D -K 6 -2 E p ro ce s s o r e nabl e s h ig he r p ro c e s s o r c o re
performance and promotes straightforward extensibility in
future designs. Instead of directly executing complex x86
instruct ions, which have lengths of 1 to 15 bytes, the
AMD-K6-2E processor executes the simpler and easier
fixed-length RISC86 opcodes, while maintaining the instruction
coding efficiencies found in x86 programs.
The AMD-K6-2E processor contains parallel decoders, a
centralized RISC86 operation scheduler, and ten execution
units that support superscalar operation—multiple decode,
execution, and retirement—of x86 instructions. These elements
are packed into an aggressive and highly efficient six-stage
pipeline.
As shown in Figure 1 on page 9, the high-performance,
out-of-order execution engine of the AMD-K6-2E processor is
mated to a split level-one 64-Kbyte writeback cache with 32
Kbytes of instruction cache and 32 Kbytes of data cache. The
instruction cache feeds the decoders and, in turn, the decoders
feed the scheduler. The Instruction Control Unit (ICU) issues
and retires RISC86 operations contained in the scheduler. The
system bus interface is an industry-standard 64-bit Super7 and
Socket 7 demultiplexed bus.
The AMD-K6-2E processor combines the latest in processor
microarchitecture to provide the highest x86 performance for
today’s computational systems. The AMD-K6-2E offers true
sixth-generation performance and x86 binary software
compatibility.
Preliminary Information
Internal Architecture
22529B/0—January 2000
Chapter 2