| 摘要 |
PROBLEM TO BE SOLVED: To maintain the combination of duty ratios of a plurality of PWM signals normal at all times by prohibiting by a data transfer control means the data transfer wherein the contents stored in a first storage circuit is transferred to a second storage circuit which is conducted synchronously with an overflow signal or a downflow signal of a counting means. SOLUTION: A specified reference clock signal 101 is input into a counter 102 and is counted. The counted value is compared with the values of compare resistors A103, B104 by comparators A105, B106 respectively and then coincidence signals 115, 116 are output from the comparators A105, B106 respectively. The coincidence signals 115, 116 and an overflow signal of the counter 102 are output to controlling circuits A110, B111 and then the waveforms of PWM signals are controlled by the output control circuits A110, B111 and specified PWM signals are output through output terminals 113, 114. At that time, the data transfer from master resistors 103a, 104a to slave resistors 103b, 104b which is synchronous with the overflow signal of the counter 102 is prohibited. |
