Table 7-4. Atx Fsc Settings - Intel E1400 - Celeron 2.0GHz 800MHz 512KB Socket 775 Dual-Core CPU Design Manual

Table 7-4. ATX FSC Settings

Parameter
T
HIGH
T
LOW
Minimum PWM Duty
Cycle
PWM Frequency
Spin-up time
T
AVERAGING
When T
SENSOR
All Fans ON
Hysteresis
Offset
NOTES:
1.
2.
3.
4.
5.
6.
118
Classification
Required
Required
Required
Required
Suggested
Suggested
< T Suggested
LOW
Suggested
Suggested
Required
A PWM frequency of 25 kHz is the design target for the reference and for the Intel
Boxed Processor and the reference design.
Use the lowest time available in this range for the device selected.
To ensure compliance with the thermal specification, thermal profile and usage of the
T for fan speed control these setting should not be user configurable.
SENSOR
If present in the FSC device the Thermal Diode Correction Factor should be input to this
register.
If the FSC device does not have a means to input a fixed temperature offset then:
T = T + Thermal Diode Correction Factor and
HIGH CONTROL
T = T
+ Thermal Diode Correction Factor.
LOW CONTROL
If this function is present on the device it must be enabled
Legacy Fan Speed Control
Processor Thermal
Sensor
T
CONTROL
T – 10 °C
CONTROL
250 – ~500 ms
35 sec
Minimum PWM%
T + 3 °C
CONTROL
2 °C
Thermal Diode
Correction Factor
Thermal and Mechanical Design Guidelines
PWM Output Notes
3, 5
3,5
20%
21–28 kHz 1
2, 6
6
4, 5
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