Table 12. Fsc Definitions - Intel QX9770 - Core 2 Extreme Quad-Core Processor Design Manual

To use all of the features in the Intel reference heatsink design or the Boxed
Processor, system integrators should verify the following functionality is present in the
board design. Refer to the Fan Specification for 4 wire PWM Controlled Fans and
Chapter 5 for complete details on the Intel enabled thermal solution.
The FSC definitions are listed in Table 12.

Table 12. FSC Definitions

Item
T
SENSOR
T
CONTROL
T
LOW
Hysteresis
T
HIGH
All Fans ON
Min PWM
Spin-up
PWM Freq
T
AVERAGING
104
Temperature reported from the processor digital thermal sensor.
T is the specification limit for use with the digital thermal sensor
CONTROL
The temperature above which the fan will begin to accelerate in response to the
digital thermal sensor temperature.
The number of degrees below T
down.
The temperature at which the fan is operating at full speed (100% PWM Duty
Cycle). By specification this is Tcontrol.
The processor temperature at which all fans in the system are increased to 100%
Duty Cycle.
Minimum pulse width modulation (% duty cycle) that the fans will run at when
T is less than T .
SENSOR LOW
Amount of time fan is run at 100% duty cycle to overcome fan inertia.
The operating frequency of the PWM signal.
The time (in seconds) that elapses while the fan is gradually sped up in response
to a processor temperature spike.
Legacy Fan Speed Control
Definition
the fans will remain on before slowing
CONTROL
Thermal and Mechanical Design Guidelines