INTERRUPT CONTROL SYSTEM

PURPOSE:To realize an interrupt control system without contention between transmission interrupt and reception interrupt by generating the transmission interrupt and the reception interrupt synchronously with the leading and trailing of a communication speed clock. CONSTITUTION:The system is provided with a clock generating circuit 20 consisting of a means generating a clock whose frequency is a multiple of (n) of the communication speed, a means supplying eight clocks whose frequency is a multiple of (n) of the communication speed as the transmission timing signal in the timing of the leading of the clock whose frequency is a multiple of (1/n) of the communication speed to a 1st serial interface section 12, and a means supplying eight clocks whose frequency is a multiple of (n) of the communication speed is the reception timing signal in the timing of the trailing of the clock whose frequency is a multiple of (1/n) of the communication speed. Then each of the leading and the trailing of 1/8 clock is used for the interrupt signal at transmission and reception respectively. Thus, the contention of the transmission interrupt and reception interrupt of the data is avoided.