Artesyn NITX-315/NITX-315-ET Installation and Use (August 2014) - Manual (Page 35)

Hardware Preparation and Installation
NITX-315/NITX-315-ET Installation and Use (6806800L71D) 35
A PNP thermal transistor is integrated in Tunnel Creek; it is used as a diode and it connects to
an external digital thermal sensor (EMC2103). The CPU can get the data of junction
temperature through the SM bus. Note that this is an inaccurate value and the temperature
offset must be taken into account through the reading of the CPU’s MSR.
Intel Thermal Monitor: Intel thermal monitor controls processor temperature by modulating
(starting and stopping) the processor core clocks when the processor silicon reaches its
maximum operating temperature. Signal "PROCHOT #" is used in this mode, when the
processor temperature goes up to 110C, the PROCHOT# is output and active, it indicates that
the processor thermal control circuit is activated. A red LED D2 can show the "processor hot"
status.
When the CPU junction temperature is more than 125°C, CPU will assert the THERMTRIP#, and
the onboard logic will shut down the system power, the LED D8 shows this status.
Table 2-5 Onboard LED Definition
LED Definition Status Description
D2 'PROCHOT' signal is active ON The CPU temperature goes up to 110°C
OFF Normal status
D8 'THERMTRIP#' signal is active ON The CPU temperature goes up to 125°C
OFF Normal status