What's the built-in limit?
Depends on the core. And I'm not sure what it is for each. I'd guess
somewhere between 70-95C. It might be in the model specs somewhere. I
think this is how it works, but don't hold me to it.
Thermtrip (Thermtp) Bit 1. Set to 1 if a temperature sensor trip occurs
and was enabled.
Thermtrip Sense (ThermtpSense) Bit 3. Set to 1 if a temperature sensor
trip occurs. The value of this bit is maintained through warm reset.
Thermtrip Enabled (ThermtpEn) Bit 5. Indicates that the thermtrip
temperature sensor is enabled. When this bit is set to 1, a THERMTRIP High
event will cause the hardware to shut down the PLL, assert the THERMTRIP
output pin and set the ThermtpHi bit. The ThermtpSense bit is set for a
THERMTRIP High event, irrespective of the state of ThermtpEn.
Diode Offset (DiodeOffset[5:0]) Bits 13-8.Thermal diode offset is used
to correct temperature measurement made by an external temperature sensor.
The offset is in 1 degree Celsius increments and it should be subtracted
from the temperature measurement. A correction to the offset may be needed
for some temperature sensors. Contact the temperature sensor vendor to
determine whether an offset correction is needed. The maximum allowable
offset is provided in the appropriate processor data sheet, and the
maximum offset can vary for different processors.
Software Thermtrip (SwThermtp) Bit 31. Writing a 1 to this bit position
induces a THERMTRIP event. This bit is write-only and returns 0 when read.
This is a diagnostic bit, and it should be used for testing purposes only.