Vol. 3C 35-123

MODEL-SPECIFIC REGISTERS (MSRS)

820H

2080

IA32_X2APIC_IRR0

Thread

x2APIC Interrupt Request register bits [31:0] (R/O) 

821H

2081

IA32_X2APIC_IRR1

Thread

x2APIC Interrupt Request register bits [63:32] (R/O) 

822H

2082

IA32_X2APIC_IRR2

Thread

x2APIC Interrupt Request register bits [95:64] (R/O) 

823H

2083

IA32_X2APIC_IRR3

Thread

x2APIC Interrupt Request register bits [127:96] (R/O) 

824H

2084

IA32_X2APIC_IRR4

Thread

x2APIC Interrupt Request register bits [159:128] (R/O) 

825H

2085

IA32_X2APIC_IRR5

Thread

x2APIC Interrupt Request register bits [191:160] (R/O) 

826H

2086

IA32_X2APIC_IRR6

Thread

x2APIC Interrupt Request register bits [223:192] (R/O) 

827H

2087

IA32_X2APIC_IRR7

Thread

x2APIC Interrupt Request register bits [255:224] (R/O) 

828H

2088

IA32_X2APIC_ESR

Thread

x2APIC Error Status register (R/W) 

82FH

2095

IA32_X2APIC_LVT_CMCI

Thread

x2APIC LVT Corrected Machine Check Interrupt register (R/W) 

830H

2096

IA32_X2APIC_ICR

Thread

x2APIC Interrupt Command register (R/W) 

832H

2098

IA32_X2APIC_LVT_TIMER

Thread

x2APIC LVT Timer Interrupt register (R/W) 

833H

2099

IA32_X2APIC_LVT_THERM

AL

Thread

x2APIC LVT Thermal Sensor Interrupt register (R/W) 

834H

2100

IA32_X2APIC_LVT_PMI

Thread

x2APIC LVT Performance Monitor register (R/W) 

835H

2101

IA32_X2APIC_LVT_LINT0

Thread

x2APIC LVT LINT0 register (R/W) 

836H

2102

IA32_X2APIC_LVT_LINT1

Thread

x2APIC LVT LINT1 register (R/W) 

837H

2103

IA32_X2APIC_LVT_ERROR

Thread

x2APIC LVT Error register (R/W) 

838H

2104

IA32_X2APIC_INIT_COUNT

Thread

x2APIC Initial Count register (R/W) 

839H

2105

IA32_X2APIC_CUR_COUNT

Thread

x2APIC Current Count register (R/O) 

83EH

2110

IA32_X2APIC_DIV_CONF

Thread

x2APIC Divide Configuration register (R/W) 

83FH

2111

IA32_X2APIC_SELF_IPI

Thread

x2APIC Self IPI register (W/O) 

C000_

0080H

IA32_EFER

Thread

Extended Feature Enables 
See Table 35-2.

C000_

0081H

IA32_STAR

Thread

System Call Target Address (R/W) 
See Table 35-2.

C000_

0082H

IA32_LSTAR

Thread

IA-32e Mode System Call Target Address (R/W) 
See Table 35-2.

C000_

0084H

IA32_FMASK

Thread

System Call Flag Mask (R/W) 
See Table 35-2.

C000_

0100H

IA32_FS_BASE

Thread

Map of BASE Address of FS (R/W) 
See Table 35-2.

C000_

0101H

IA32_GS_BASE

Thread

Map of BASE Address of GS (R/W) 
See Table 35-2.

C000_

0102H

IA32_KERNEL_GSBASE

Thread

Swap Target of BASE Address of GS (R/W) See Table 35-2.

Table 35-13.  MSRs in Processors Based on Intel® Microarchitecture Code Name Nehalem (Contd.)

Register 

Address

Register Name

Scope

Bit Description

 Hex

Dec