60
Embedded AMD Processor Recognition
Embedded AMD-K6™ Processors BIOS Design Guide
23913A/0—November 2000
Preliminary Information
for a value of at least 8000_0001h in the EAX register returned
by function 8000_0000h.
Within AMD’s family of processors, different members can
execute a different number of functions. Table 28 summarizes
t h e C P U I D f u n c t i o ns c ur re n t ly i m p l e m e n t e d o n A M D
processors.
76
Identifying the Processor’s Vendor
Software must execute the standard function EAX=0. The
CPUID instruction returns a 12-character string that identifies
the processor’s vendor. The instruction also returns the largest
s ta n da rd f un c ti o n in p ut va l ue d e fi ne d fo r th e C P U I D
instruction on the processor.
For AMD processors, function 0 returns a vendor string of
“AuthenticAMD”. This string informs the software to follow
Table 28. CPUID Functions
1
in AMD-K6™ Processors
2
Notes:
1. “Appendix A” on page 71 contains detailed descriptions of the functions.
2. Future versions of these processors may implement additional functions.
Standard
Function
Extended
Function
Description
AMD-K6™E
Processor
(Model 7)
AMD-K6™-2
and
AMD-K6™-2E
Processors
(Model 8)
AMD-K6™
-III
Processor
(Model 9)
AMD-K6™-2E+
and
AMD-K6™-
III
E+
Processors
(Model D)
0
—
Vendor String and Largest
Standard Function Value
X
X
X
X
1
—
Processor Signature and Standard
Feature Bits
X
X
X
X
—
8000_0000h Largest Extended Function Value
X
X
X
X
—
8000_0001h
Extended Processor Signature and
Extended Feature Bits
X
X
X
X
—
8000_0002h Processor Name
X
X
X
X
—
8000_0003h Processor Name
X
X
X
X
—
8000_0004h Processor Name
X
X
X
X
—
8000_0005h L1 TLB
3
Cache Information
3. TLB = translation lookaside buffer
X
X
X
X
—
8000_0006h L2 TLB
3
Cache Information
—
—
X
X
—
8000_0007h AMD PowerNow! Technology
—
—
—
X
4
4. Low-power versions only