System Considerations - Kontron CP6500-V User Manual

CP6500-V
7.

System Considerations

The following chapters provide system integrators with the necessary information to satisfy
thermal requirements when implementing CP6500-V applications.
7.1 Passive Thermal Regulation
The thermal management architecture implemented on the CP6500-V can be described as be-
ing two separate but related functions. The goal of the two functions is to protect the processor
and reduce processor power consumption. Enabling the thermal control circuit allows the pro-
cessor to maintain a safe operating temperature without the need for special software drivers
or interrupt handling routines.
The two thermal protection functions provided by the processor are:
1. External (W83627HF) thermal monitor:
This function controls via the processor Stopclock signal the power consumption. While
asserted, it has the effect of stopping the clock to many internal elements of the proces-
sor.
2. Thermtrip:
In the event of a cooling failure resulting in extreme overheating, the processor will auto-
matically shut down when the die temperature has reached approximately 135 °C. This
event is known as "Thermtrip".
7.1.1 CPU External Thermal Supervision
This function can be enabled and disabled in the BIOS, whereby the default value is: enabled.
There is one thermal sensor in the Celeron processor, namely the on-die thermal diode.
When the external thermal control circuit has been enabled and a high temperature situation
occurs, the front panel "TH" LED will be switched on and the external Stopclock signal of the
processor will be modulated by alternately turning the clocks off and on at a duty cycle specified
in the BIOS (25% - 75%) and the processor power dissipation will be reduced.
The thermal control circuit does not automatically go inactive once the temperature goes below
the selected external thermal supervision point. Explicit software action is necessary to switch
back to normal mode.
Note ...
The duty cycle and the external thermal supervision point can be configured in
the BIOS. For all Celeron processors, the default external thermal supervision
point is 100 °C.
ID 28945, Rev. 01 © 2005 Kontron Modular Computers GmbH
System Considerations
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