Intel 64 and IA-32 Architectures Software Developers Manual Volume 3B, System Programming Guide Part 2

Table Of Contents
Vol. 3 B-95
MODEL-SPECIFIC REGISTERS (MSRS)
2CH 44 MSR_EBC_
FREQUENCY_ID
0, 1 Shared Processor Frequency
Configuration. (R)
The bit field layout of this MSR
varies according to the MODEL
value of the CPUID version
information. This bit field layout
applies to Pentium 4 and Xeon
Processors with MODEL encoding
less than 2.
Indicates current processor
frequency configuration.
20:0 Reserved.
23:21 Scalable Bus Speed. (R/W)
Indicates the intended scalable
bus speed:
Encoding Scalable Bus Speed
000B 100 MHz
All others values reserved.
63:24 Reserved.
3AH 58 IA32_FEATURE_
CONTROL
3, 4, 6 Unique Control Features in IA-32
Processor. (R/W). see Table B-2
(If CPUID.01H:ECX.[bit 5])
79H 121 IA32_BIOS_UPDT_
TRIG
0, 1, 2,
3, 4, 6
Shared BIOS Update Trigger Register.
(R/W) see Table B-2
8BH 139 IA32_BIOS_SIGN_ID 0, 1, 2,
3, 4, 6
Unique BIOS Update Signature ID. (R/W)
see Table B-2
9BH 155 IA32_SMM_MONITOR_
CTL
3, 4, 6 Unique SMM Monitor Configuration.
(R/W). see Table B-2
FEH 254 IA32_MTRRCAP 0, 1, 2,
3, 4, 6
Unique MTRR Information.
See Section 10.11.1, “MTRR
Feature Identification..
Table B-6. MSRs in the Pentium 4 and Intel Xeon Processors (Contd.)
Register
Address
Register Name
Fields and Flags
Model
Avail-
ability
Shared/
Unique
1
Bit Description
Hex Dec