C47
What you ask is not technically feasible sensor chips of a chip - they measure the current temperature of the crystal, and that the temperature of the motherboard, or rather air at its surface is needed physically isolated from their probe, such as a thermal diode or a thermistor (ideal thermocouple, but firstly its output voltage 17 - 67 mkV depending of the applied alloy, and the main thing is the individual nonlinear elements described by differential equations of the thirty-fifth (Chrome-Allyumel, Chrome-Kopel) - thirty-eighth order (Platinum - Platinum-Rhodium) that requires a special measuring circuits compensation thermoelectric contacts and volumetric conversion tables for thermoelectric power - temperature) that usually does not make much sense because of technical measure the temperature in the housing and can be external to the system board temperature sensor.