64
Embedded AMD Processor Recognition
Embedded AMD-K6 Processors BIOS Design Guide
23913A/0—November 2000
Preliminary Information
Before using any of the enhanced features added to the latest
generation of processors, software should test each feature bit
returned by functions 1 and 8000_0001h to identify the
capabilities available on the processor. For example, software
must test feature bit 23 to determine if the processor executes
the MMX technology instructions. Attempting to execute an
unavailable feature can cause errors and exceptions.
Bit 31, as returned by extended function 8000_0001h,
designates the presence of 3DNow! technology. Other processor
vendors have adopted this technology, so bit 31 is now
considered an open standard. “Appendix A” on page 71, and
“Appendix B” on page 81 contain details on bit values.
Determining Instruction Set Support
It is preferable to use CPUID feature flags as much as possible,
rather than deriving capabilities from vendor specifiers
combined with CPUID model numbers.
The AMD-K6-2E+ and AMD-K6-IIIE+ processors add a new set
of powerful extensions to the x86 instruction set—3DNow!
extensions. See the
AMD Extensions to the 3DNow! and
MMX Instruction Sets Manual
, order# 22466 for more
information about these new instructions.
23
24
MMX Instructions
FXSAVE/FXRSTOR
The MMX instruction set is supported.
Fast floating-point save and restore is supported.
Streaming single instruction multiple data (SIMD)
extensions (SSE) are supported
1
1
1
1
25
Streaming SIMD extensions (SSE)
0
0
26
Reserved on all AMD processors
AMD 3DNow! Instruction
Extensions
AMD 3DNow! Instructions
0
0
30
Digital signal processing (DSP) extensions to the
3DNow! instruction set are supported.
3
3DNow! instructions are supported.
0
1
31
0
1
Notes:
1.
2. Bit definitions: 0 = No Support, 1 = Support
3. For more information on these instructions, see the
AMD Extensions to the 3DNow! and MMX Instructions Sets Manual,
order#
22466.
“Appendix A” on page 71 contains details on bit values.
Table 30. Standard and Extended Feature Bits (continued)
Bit
1
Feature
Description
Standard
2
Extended
2