35-202 Vol. 3C
MODEL-SPECIFIC REGISTERS (MSRS)
63:30
Reserved.
6B1H
1713
MSR_RING_PERF_LIMIT_REA
SONS
Package
Indicator of Frequency Clipping in the Ring Interconnect (R/W)
(frequency refers to ring interconnect in the uncore)
0
PROCHOT Status (R0)
When set, frequency is reduced below the operating system
request due to assertion of external PROCHOT.
1
Thermal Status (R0)
When set, frequency is reduced below the operating system
request due to a thermal event.
5:2
Reserved.
6
VR Therm Alert Status (R0)
When set, frequency is reduced below the operating system
request due to a thermal alert from the Voltage Regulator.
7
Reserved.
8
Electrical Design Point Status (R0)
When set, frequency is reduced below the operating system
request due to electrical design point constraints (e.g. maximum
electrical current consumption).
9
Reserved.
10
Package-Level Power Limiting PL1 Status (R0)
When set, frequency is reduced below the operating system
request due to package-level power limiting PL1.
11
Package-Level PL2 Power Limiting Status (R0)
When set, frequency is reduced below the operating system
request due to package-level power limiting PL2.
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.
19:18
Reserved.
20
Graphics Driver Log
When set, indicates that the Graphics Driver Status bit has
asserted since the log bit was last cleared.
This log bit will remain set until cleared by software writing 0.
Table 35-28. MSRs Supported by 4th Generation Intel® Core™ Processors (Haswell microarchitecture) (Contd.)
Register
Address
Register Name
Scope
Bit Description
Hex
Dec