| 摘要 |
<P>PROBLEM TO BE SOLVED: To surely start an A/D conversion in combining the specified ON and OFF of a predetermined PWM signal, in an inverter control semiconductor in which the pulse width of a PWM signal is controlled based on a digital value in an A/D converter. <P>SOLUTION: When a counter 3 for generating a PWM signal counts a prescribed counter value, a timer 21 receives a signal from the counter 3 and starts counting. Based on a duty setting value stored in a duty setting register (7U in a U-phase) of a PWM signal generating circuit, the timer period of the timer 21 is computed, and the timer period is stored in a timer period setting register 22. When the timer 21 counts the timer period stored in the timer period setting register 22, the timer 21 instantaneously generates an A/D conversion starting factor and outputs it to a corresponding A/D converter 1g to start A/D conversion. As a result, A/D conversions at more minute timings becomes possible. <P>COPYRIGHT: (C)2003,JPO |
