Intel® Pentium® Silver and Intel® Celeron® Processors Datasheet, Volume 1
Thermal Trip Signal (PCHHOT_N)
The PCH provides PCHHOT_N signal to indicate that it has exceeded some temperature limit. The limit is set by BIOS. The temperature limit (programmed into the PHL register) is compared to the present temperature. If the present temperature is greater than the PHL value then the pin is asserted.
PCHHOT_N is an O/D output and requires a Pull-up on the motherboard.
The PCH evaluates the temperature from the thermal sensor against the programmed temperature limit every one second.