Intel L7700 LE80537LG0334M 사용자 설명서

88

Datasheet

designed thermal solution that is not able to prevent excessive activation of the TCC in 

the anticipated ambient environment may cause a noticeable performance loss and 

may affect the long-term reliability of the processor. In addition, a thermal solution that 

is significantly under designed may not be capable of cooling the processor even when 

the TCC is active continuously.

The Intel Thermal Monitor controls the processor temperature by modulating (starting 

and stopping) the processor core clocks or by initiating an Enhanced Intel SpeedStep 

Technology transition when the processor silicon reaches its maximum operating 

temperature. The Intel Thermal Monitor uses two modes to activate the TCC: 

Automatic mode and on-demand mode. If both modes are activated, automatic mode 

takes precedence. 

The Intel Thermal Monitor automatic mode must be enabled through BIOS for the 

processor to be operating within specifications. 

There are two automatic modes called Intel Thermal Monitor 1 and Intel Thermal 

Monitor 2. These modes are selected by writing values to the MSRs of the processor. 

After automatic mode is enabled, the TCC will activate only when the internal die 

temperature reaches the maximum allowed value for operation. 

Likewise, when Intel Thermal Monitor 2 is enabled and a high temperature situation 

exists, the processor will perform an Enhanced Intel SpeedStep Technology transition 

to a lower operating point. When the processor temperature drops below the critical 

level, the processor will make an Enhanced Intel SpeedStep Technology transition to 

the last requested operating point. 

Intel Thermal Monitor 1 and Intel Thermal Monitor 2 can co-exist within the processor. 

If both Intel Thermal Monitor 1 and Intel Thermal Monitor 2 bits are enabled in the 

auto-throttle MSR, Intel Thermal Monitor 2 will take precedence over Intel Thermal 

Monitor 1. However, if Intel Thermal Monitor 2 is not sufficient to cool the processor 

below the maximum operating temperature then Intel Thermal Monitor 1 will also 

activate to help cool down the processor. Intel recommends Intel Thermal Monitor 1 

and Intel Thermal Monitor 2 be enabled on the processors. 

If a processor load based Enhanced Intel SpeedStep Technology transition (through 

MSR write) is initiated when an Intel Thermal Monitor 2 period is active, there are two 

possible results:

1. If the processor load based Enhanced Intel SpeedStep Technology transition target 

frequency is higher than the Intel Thermal Monitor 2 transition based target 

frequency, the processor load-based transition will be deferred until the Intel 

Thermal Monitor 2 event has been completed.

2. If the processor load-based Enhanced Intel SpeedStep Technology transition target 

frequency is lower than the Intel Thermal Monitor 2 transition based target 

frequency, the processor will transition to the processor load-based Enhanced Intel 

SpeedStep Technology target frequency point.

When Intel Thermal Monitor 1 is enabled while a high temperature situation exists, the 

clocks will be modulated by alternately turning the clocks off and on at a 50% duty 

cycle. Cycle times are processor speed dependent and will decrease linearly as 

processor core frequencies increase. Once the temperature has returned to a non-

critical level, modulation ceases and TCC goes inactive. A small amount of hysteresis 

has been included to prevent rapid active/inactive transitions of the TCC when the 

processor temperature is near the trip point. The duty cycle is factory configured and 

cannot be modified. Also, automatic mode does not require any additional hardware, 

software drivers, or interrupt handling routines. Processor performance will be 

decreased by the same amount as the duty cycle when the TCC is active.