US Patent 7165183 Temperature controlled semiconductor circuit

An interrupt signal EMG is put out to a microprocessor 10 when a thermal monitor 40 detects that a package temperature exceeds a reference. The microprocessor then increases a frequency division value N stored in a frequency division value register 31 of a clock mechanism 30. An inputted clock signal MCK is divided by N to generate a system clock signal SCK. Therefore, the frequency of system clock signal SCK decreases when N increases. Consequently, electricity consumption of each function module 20i decreases and the package temperature is reduced.