Intel 253666-024US User Manual

Page 213

Vol. 2A 3-167

INSTRUCTION SET REFERENCE, A-M

CPUID—CPU Identification

EDX

Bits 10-0: Reserved

Bit 11: SYSCALL/SYSRET available (when in 64-bit mode)

Bits 19-12: Reserved = 0

Bit 20: Execute Disable Bit available

Bits 28-21: Reserved = 0
Bit 29: Intel

64 Technology available = 1

Bits 31-30: Reserved = 0

80000002H EAX

EBX

ECX

EDX

Processor Brand String

Processor Brand String Continued

80000003H EAX

EBX

ECX

EDX

Processor Brand String Continued

80000004H EAX

EBX

ECX

EDX

Processor Brand String Continued

80000005H EAX

EBX

ECX

EDX

Reserved = 0

80000006H EAX

EBX

Reserved = 0

ECX

EDX

Bits 7-0: Cache Line size in bytes

Bits 15-12: L2 Associativity field *

Bits 31-16: Cache size in 1K units

Reserved = 0

NOTES:

L2 associativity field encodings:

00H - Disabled

01H - Direct mapped

02H - 2-way

04H - 4-way

06H - 8-way

08H - 16-way

0FH - Fully associative

Table 3-12. Information Returned by CPUID Instruction (Contd.)

Initial EAX

Value

Information Provided about the Processor