New Instructions
3-29
18524C/0—Nov1996
AMD-K5 Processor Technical Reference Manual
3.3.1
CPUID
mnemonic
opcode
description
CPUID
0FA2h
Identify processor
Privilege:
CPL=0
Registers Affected:
EAX, EBX, ECX, EDX
Flags Affected:
none
Exceptions Generated: Real, Virtual-8086 mode—none
Protected mode—none
The CPUID instruction identifies the type of processor and the features it supports.
A 0 or 1 value written to the EAX register specifies what information will be
returned by the instruction.
The processor implements the ID flag (bit 21) in the EFLAGS register. By writing and
reading this bit, software can verify that the processor will execute the CPUID
instruction.
For detailed instructions on processor and feature identification see the AMD Proces-
sor Recognition application note, order# 20734.
Table 3-8 outlines the AMD-K5 processor family codes and model codes with the
CPU clock frequencies (MHz), bus frequencies (MHz), and P-rating strings (“Pxxx”).
Table 3-8.
CPU Clock Frequencies, Bus Frequencies, and P-Rating Strings
Family Code
Model Code
CPU Frequency (MHz) CPU Bus Frequency (MHz)
P-Rating String (“Pxxx”)
1
5
0
75
50
P75
90
60
P90
100
66
P100
1
90
60
P120
100
66
P133
120
60
P150
133
66
P166
Notes:
1. The CPUID instruction does not return a P-Rating string.
— This table does not constitute product announcements. Instead, the information in the table represents possible product offerings.
AMD will announce actual products based on availability and market demand..
Summary of Contents for AMD-K5
Page 1: ...AMD K5 Processor Technical Reference Manual TM...
Page 10: ...x AMD K5 Processor Technical Reference Manual 18524C 0 Nov1996...
Page 24: ...1 4 Overview AMD K5 Processor Technical Reference Manual 18524C 0 Nov1996...
Page 54: ...2 30 Internal Architecture AMD K5 Processor Technical Reference Manual 18524C 0 Nov1996...
Page 116: ...4 26 Performance AMD K5 Processor Technical Reference Manual 18524C 0 Nov1996...
Page 356: ...6 44 System Design AMD K5 Processor Technical Reference Manual 18524C 0 Nov1996...
Page 380: ...7 24 Test and Debug AMD K5 Processor Technical Reference Manual 18524C 0 Nov1996...
Page 396: ...A 16 AMD K5 Processor Technical Reference Manual 18524C 0 Nov1996...
Page 406: ...I 10 Index AMD K5 Processor Technical Reference Manual 18524C 0 Nov1996...