Intel 4 HT 631 80552PG0802M2M Scheda Tecnica

Datasheet

81

 

The PROCHOT# signal is asserted when a high temperature situation is detected, 

regardless of whether Thermal Monitor or Thermal Monitor 2 is enabled.

Note that the Thermal Monitor 2 TCC cannot be activated via the on demand mode. The 

Thermal Monitor TCC, however, can be activated through the use of the on demand 

mode.

The processor provides an auxiliary mechanism that allows system software to force 

the processor to reduce its power consumption. This mechanism is referred to as “On-

Demand” mode and is distinct from the Thermal Monitor feature. On-Demand mode is 

intended as a means to reduce system level power consumption. Systems using the 

Pentium 4 processor must not rely on software usage of this mechanism to limit the 

processor temperature.

If bit 4 of the ACPI P_CNT Control Register (located in the processor 

IA32_THERM_CONTROL MSR) is written to a '1', the processor immediately reduces its 

power consumption via modulation (starting and stopping) of the internal core clock, 

independent of the processor temperature. When using On-Demand mode, the duty 

cycle of the clock modulation is programmable via bits 3:1 of the same ACPI P_CNT 

Control Register. In On-Demand mode, the duty cycle can be programmed from 12.5% 

on/87.5% off, to 87.5% on/12.5% off in 12.5% increments. On-Demand mode may be 

used in conjunction with the Thermal Monitor. If the system tries to enable On-Demand 

mode at the same time the TCC is engaged, the factory configured duty cycle of the 

TCC will override the duty cycle selected by the On-Demand mode. 

VID

Frequency

Temperature

T

TM2

f

MAX

f

TM2

VID

VID

TM2

PROCHOT#