CPUID Identification Algorithms
11
23913A/0—November 2000
Embedded AMD-K6™ Processors BIOS Design Guide
Preliminary Information
CPUID Identification Algorithms
The CPUID instruction provides information about the
processor (vendor, type, name, etc.) and its capabilities
(features). After detecting the processor and its capabilities,
software can be accurately tuned to the system for maximum
p e r fo r m a n c e a n d b e n e f i t t o u s e rs . Fo r m o re d e t a i l e d
i n fo r m a t i o n a b o u t u s i n g t h e C P U I D i n s t r u c t i o n , s e e
“Embedded AMD Processor Recognition” on page 57.
To determine if the processor is enabled with AMD PowerNow!
technology, use CPUID function 8000_0007, as described on
page 79.
The recommended boot strings (or processor names) to be
displayed for AMD-K6 processors are shown in Table 5.
For example, a BIOS boot string for a Model 9, stepping 3, 450-
MHz AMD-K6-III processor would look like this:
■
AMD-K6(tm)-III/450
Fi gure 1 o n p ag e 1 2 show s a f low char t for t h e C PUI D
instruction. Use this chart to implement a CPUID algorithm.
Table 5.
Recommended Boot Strings for AMD-K6™ Processors
Model
Recommended Boot String Display
1
Notes:
1. The value for XXX is determined by calculating the core frequency of the processor. Use the Time
Stamp Counter (TSC) to ‘clock’ a timed operation and compare the result to the real-time clock
(RTC) to determine the operating frequency.
Model 7
AMD-K6(tm)/XXX
All steppings of Models 8
AMD-K6(tm)-2/XXX
Model D/[7:4]
2
2. See “Functions 8000_0002h, 8000_0003h, and 8000_0004h — Processor Name String” on page 77
for more information about these steppings.
AMD-K6(tm)-2+/XXX
Model 9/[3:0]
AMD-K6(tm)-III/XXX
Model D/[3:0]
2
AMD-K6(tm)-III+/XXX