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Vol. 3C 35-255

MODEL-SPECIFIC REGISTERS (MSRS)

1

Thermal Status (R0)
When set, frequency is reduced due to a thermal event.

4:2

Reserved.

5

Running Average Thermal Limit Status (R0) 
When set, frequency is reduced due to running average thermal 

limit. 

6

VR Therm Alert Status (R0)
When set, frequency is reduced due to a thermal alert from a 

processor Voltage Regulator.

7

VR Thermal Design Current Status (R0)
When set, frequency is reduced due to VR TDC limit.

8

Other Status (R0)
When set, frequency is reduced due to electrical or other 

constraints.

9

Reserved.

10

Package/Platform-Level Power Limiting PL1 Status (R0)
When set, frequency is reduced due to package/Platform-level 

power limiting PL1.

11

Package/Platform-Level PL2 Power Limiting Status (R0)
When set, frequency is reduced due to package/Platform-level 

power limiting PL2/PL3.

15:12

Reserved 

16

PROCHOT Log 
When set, indicates that the PROCHOT Status bit has asserted 

since the log bit was last cleared.
This log bit will remain set until cleared by software writing 0.

17

Thermal Log 
When set, indicates that the Thermal Status bit has asserted since 

the log bit was last cleared.
This log bit will remain set until cleared by software writing 0.

20:18

Reserved.

21

Running Average Thermal Limit Log 
When set, indicates that the RATL Status bit has asserted since the 

log bit was last cleared.
This log bit will remain set until cleared by software writing 0.

22

VR Therm Alert Log 
When set, indicates that the VR Therm Alert Status bit has 

asserted since the log bit was last cleared.
This log bit will remain set until cleared by software writing 0.

Table 35-37.  Additional MSRs Supported by 6th Generation Intel® Core™ Processors Based on Skylake 

Microarchitecture

Register 

Address

Register Name

Scope

Bit Description

 Hex

Dec