Intel I7-900 DESKTOP PROCESSOR - DATASHEET VOLUME 2 Datasheet page 94

2.13.5 MC_THERMAL_PARAMS_B0
MC_THERMAL_PARAMS_B1
MC_THERMAL_PARAMS_B2
Parameters used by the thermal throttling logic.
Device:
Function: 3
Offset:
Access as a Dword
Bit
31:26
25:16
15:8
7:0
2.13.6 MC_COOLING_COEF0
MC_COOLING_COEF1
MC_COOLING_COEF2
Heat removed from DRAM 8 DCLKs. This should be scaled relative to the per command
weights and the initial value of the throttling threshold. This includes idle command and
refresh energies. If 2X refresh is supported, the worst case of 2X refresh must be
assumed.
When there are more than 4 ranks attached to the channel, the thermal throttle logic is
shared.
Device:
Function: 3
Offset:
Access as a Dword
Bit
31:24
23:16
15:8
7:0
94
4, 5, 6
64h
Reset
Type
Value
SAFE_INTERVAL.
Safe values for cooling coefficient and duty cycle will be applied while the
SAFE_INTERVAL is exceeded. This interval is the number of ZQ intervals since
the last time the MC_COOLING_COEF or MC_CLOSED_LOOP registers have
been written. A register to write to MC_COOLING_COEF or MC_CLOSED_LOOP
RW 1
will re-apply the normal MC_COOLING_COEF and
MC_CLOSED_LOOP.MIN_THROTTLE_DUTY_CYC values. The register value
written need not be different; writing the current value will suffice. The
MC_THERMAL_STATUS.CYCLES_THROTTLED field is reloaded when the number
of ZQ intervals exceeds this value. This field must not be programmed to 0; this
value is illegal.
SAFE_DUTY_CYC. This value replaces
RW 255
MC_CLOSED_LOOP.MIN_THROTTLE_DUTY_CYC while the
MC_THERMAL_PARAMS_B.SAFE_INTERVAL is exceeded.
SAFE_COOL_COEF.
RW 1
This value replaces MC_COOLING_COEF while the
THERMAL_PARAMS_B.SAFE_INTERVAL is exceeded.
ACTCMD_ENERGY.
RW 0
Energy of an Activate/Precharge Cycle.
4, 5, 6
80h
Reset
Type
Value
RW 255
RANK3. Rank 3 Cooling Coefficient.
RW 255
RANK2. Rank 2 Cooling Coefficient.
RW 255 RANK1. Rank 1 Cooling Coefficient.
RW 255 RANK0. Rank 0 Cooling Coefficient.
Register Description
Description
Description
Datasheet