Pulse width modulation signal generator in microcomputer for invertor, sets or resets pulse width modulation signal using period or duty coincidence signal and resets timer to zero using either of coincidence signal

摘要

A CPU starts timer measuring period and duty of PWM signal. Forwarding control circuit outputs forwarding enable signal to control input operation of period and duty setting registers (REGC,REGD), based on operation enable signal, duty and period coincidence and write-in signals. PWM signal is set or reset using period or duty coincidence signal. Timer is reset to zero using period or coincidence signal. The period and duty setting registers input period and duty of pulse width modulation (PWM) signal into following period and following duty setting registers (BFREGC,BFREGD), respectively. The period and duty comparators (1,2) generate period and duty coincidence signals when period and duty values measured by timer conforms with the values stored in corresponding registers. The period and duty write-in signals indicate write-in operation of period and duty values into following period and duty setting registers.