35-10 Vol. 3C

MODEL-SPECIFIC REGISTERS (MSRS)

3:1

On-Demand Clock Modulation Duty Cycle: 

Specific encoded values for target duty 

cycle modulation.

If CPUID.01H:EDX[22] = 1

4

On-Demand Clock Modulation Enable: Set 1 

to enable modulation.

If CPUID.01H:EDX[22] = 1

63:5

Reserved.

19BH

411

IA32_THERM_INTERRUPT

Thermal Interrupt Control (R/W)
Enables and disables the generation of an 

interrupt on temperature transitions 

detected with the processor’s thermal 

sensors and thermal monitor. 
See Section 14.7.2, “Thermal Monitor.”

If CPUID.01H:EDX[22] = 1

0

High-Temperature Interrupt Enable

If CPUID.01H:EDX[22] = 1

1

Low-Temperature Interrupt Enable

If CPUID.01H:EDX[22] = 1

2

PROCHOT# Interrupt Enable

If CPUID.01H:EDX[22] = 1

3

FORCEPR# Interrupt Enable

If CPUID.01H:EDX[22] = 1

4

Critical Temperature Interrupt Enable

If CPUID.01H:EDX[22] = 1

7:5

Reserved.

14:8

Threshold #1 Value

If CPUID.01H:EDX[22] = 1

15

Threshold #1 Interrupt Enable

If CPUID.01H:EDX[22] = 1

22:16

Threshold #2 Value

If CPUID.01H:EDX[22] = 1

23

Threshold #2 Interrupt Enable

If CPUID.01H:EDX[22] = 1

24

Power Limit Notification Enable

If CPUID.06H:EAX[4] = 1

63:25

Reserved.

19CH

412

IA32_THERM_STATUS

Thermal Status Information (RO)
Contains status information about the 

processor’s thermal sensor and automatic 

thermal monitoring facilities. 
See Section 14.7.2, “Thermal Monitor”

If CPUID.01H:EDX[22] = 1

0

Thermal Status (RO):

If CPUID.01H:EDX[22] = 1

1

Thermal Status Log (R/W): 

If CPUID.01H:EDX[22] = 1

2

PROCHOT # or FORCEPR# event (RO)

If CPUID.01H:EDX[22] = 1

3

PROCHOT # or FORCEPR# log (R/WC0)

If CPUID.01H:EDX[22] = 1

4

Critical Temperature Status (RO)

If CPUID.01H:EDX[22] = 1

5

Critical Temperature Status log (R/WC0)

If CPUID.01H:EDX[22] = 1

6

Thermal Threshold #1 Status (RO)

If CPUID.01H:ECX[8] = 1

7

Thermal Threshold #1 log (R/WC0)

If CPUID.01H:ECX[8] = 1

8

Thermal Threshold #2 Status (RO)

If CPUID.01H:ECX[8] = 1

9

Thermal Threshold #2 log (R/WC0)

If CPUID.01H:ECX[8] = 1

Table 35-2.  IA-32 Architectural MSRs (Contd.)

Register 

Address

Architectural MSR Name and bit 

fields 

(Former MSR Name)

MSR/Bit Description

Comment

Hex

Decimal