Vol. 3C 35-57
MODEL-SPECIFIC REGISTERS (MSRS)
35.3
MSRS IN THE 45 NM AND 32 NM INTEL
®
ATOM
™
PROCESSOR FAMILY
Table 35-4 lists model-specific registers (MSRs) for 45 nm and 32 nm Intel Atom processors, architectural MSR
addresses are also included in Table 35-4. These processors have a CPUID signature with
DisplayFamily_DisplayModel of 06_1CH, 06_26H, 06_27H, 06_35H and 06_36H; see Table 35-1.
The column “Shared/Unique” applies to logical processors sharing the same core in processors based on the Intel
Atom microarchitecture. “Unique” means each logical processor has a separate MSR, or a bit field in an MSR
governs only a logical processor. “Shared” means the MSR or the bit field in an MSR address governs the operation
of both logical processors in the same core.
C000_
0101H
IA32_GS_BASE
Unique
Map of BASE Address of GS (R/W)
See Table 35-2.
C000_
0102H
IA32_KERNEL_GSBASE
Unique
Swap Target of BASE Address of GS (R/W) See Table 35-2.
Table 35-4. MSRs in 45 nm and 32 nm Intel® Atom™ Processor Family
Register
Address
Register Name
Shared/
Unique
Bit Description
Hex
Dec
0H
0
IA32_P5_MC_ADDR
Shared
See Section 35.22, “MSRs in Pentium Processors.”
1H
1
IA32_P5_MC_TYPE
Shared
See Section 35.22, “MSRs in Pentium Processors.”
6H
6
IA32_MONITOR_FILTER_
SIZE
Unique
See Section 8.10.5, “Monitor/Mwait Address Range Determination.”
andTable 35-2
10H
16
IA32_TIME_STAMP_
COUNTER
Unique
See Section 17.15, “Time-Stamp Counter,” and see Table 35-2.
17H
23
IA32_PLATFORM_ID
Shared
Platform ID (R)
17H
23
MSR_PLATFORM_ID
Shared
Model Specific Platform ID (R)
7:0
Reserved.
12:8
Maximum Qualified Ratio (R)
The maximum allowed bus ratio.
63:13
Reserved.
1BH
27
IA32_APIC_BASE
Unique
See Section 10.4.4, “Local APIC Status and Location,” and
2AH
42
MSR_EBL_CR_POWERON
Shared
Processor Hard Power-On Configuration (R/W) Enables and
disables processor features;
(R) indicates current processor configuration.
0
Reserved.
Table 35-3. MSRs in Processors Based on Intel® Core™ Microarchitecture (Contd.)
Register
Address
Register Name
Shared/
Unique
Bit Description
Hex
Dec