The present invention provides a method, an apparatus, and a computer
program product for measuring the temperature of a microprocessor through
the use of ESD circuitry. The present invention uses diodes and an I/O
pad within ESD circuits to determine the temperature at the location of
the ESD circuitry. First, a current measuring device connects to a diode.
A user or a computer program disables the protected component or
circuitry, and subsequently applies a predetermined voltage to the I/O
pad. This creates a reverse saturation current through the diode, which
is measured by the current measuring device. From this current the user
or a computer program determines the temperature of the microprocessor at
the diode through the use of a graphical representation of diode reverse
saturation current and corresponding temperature.