Intel i7-950 AT80601002112AA Benutzerhandbuch

Datasheet 

77

When the Digital Temperature Sensor (DTS) reaches a value of 0 (DTS temperatures 

reported using PECI may not equal zero when PROCHOT# is activated, see 

 

for further details), the TCC will be activated and the PROCHOT# signal will be 

asserted. This indicates the processor temperature has met or exceeded the factory 

calibrated trip temperature and it will take action to reduce the temperature. 

Upon activation of the TCC, the processor will stop the core clocks, reduce the core 

ratio multiplier by 1 ratio and restart the clocks. All processor activity stops during this 

frequency transition, which occurs within 2 us. Once the clocks have been restarted at 

the new lower frequency, processor activity resumes while the voltage requested by the 

VID lines is stepped down to the minimum possible for the particular frequency. 

Running the processor at the lower frequency and voltage will reduce power 

consumption and should allow the processor to cool off. If after 1 ms the processor is 

still too hot (the temperature has not dropped below the TCC activation point, DTS 

still = 0 and PROCHOT is still active), then a second frequency and voltage transition 

will take place. This sequence of temperature checking and Frequency/VID reduction 

will continue until either the minimum frequency has been reached or the processor 

temperature has dropped below the TCC activation point.

If the processor temperature remains above the TCC activation point even after the 

minimum frequency has been reached, then clock modulation (described below) at that 

minimum frequency will be initiated.

There is no end user software or hardware mechanism to initiate this automated TCC 

activation behavior. 

A small amount of hysteresis has been included to prevent rapid active/inactive 

transitions of the TCC when the processor temperature is near the TCC activation 

temperature. Once the temperature has dropped below the trip temperature, and the 

hysteresis timer has expired, the operating frequency and voltage transition back to 

the normal system operating point using the intermediate VID/frequency points. 

Transition of the VID code will occur first, to insure proper operation as the frequency is 

increased. Refer to 

 for an illustration of this ordering.

f

MAX

f

1

f

2

VIDf

MAX

VIDf

2

VIDf

1

f

MAX

f

1

f

2

VIDf

MAX

VIDf

2

VIDf

1