To provide a clock control circuit for controlling the frequency of the clock signals of a microprocessor.

This clock control circuit 101 controls the frequency of timing signals supplied to a clock generator and distribution unit 106 and the unit 106 supplies internal clock signals to the CPU core 102 of the microprocessor. A heat sensor 134 is integrated with a semiconductor die and the output signals are supplied to main and auxiliary temperature indicator units 130 and 132. The indicator units 130 and 132 respectively assert main and auxiliary indicator signals when the temperature of the die exceeds a main threshold value level and an auxiliary threshold value level. The main and auxiliary indicator units 130 and 132 are respectively related with hysteresis characteristics for which the main and auxiliary indicator signals are not de-asserted when they are asserted once until the temperature of the die becomes lower than prescribed first and second hysteresis points.