A process corner estimation circuit with temperature compensation is
included in each die formed from a silicon wafer in order to quickly and
easily provide a determination of process corner. The temperature
compensation circuitry provides input current to a clock generator, the
input current to the clock generator being inversely proportional to the
temperature of the die. The clock generator circuit of the indicator
circuit includes an array of flip-flop elements and is run at a lower
operating voltage, such that the differences in delay in the generated
timing signal are accentuated for different process corners. The period
of the timing signal is determined using slow and fast clock counters,
with the slow clock counting a number of cycles of the timing signal and
the fast clock counting a number of cycles of a fixed frequency. The
count produced by the fast clock corresponds to the delay in the clock
generator circuit, giving a temperature compensated indication of the
process corner of the die.