| 摘要 |
<p>PURPOSE:To prevent a device which operates by switching asynchronous clocks from being malfunctioned by providing a flip-flop and preventing a clock which contains short-synchronism pulses from being supplied. CONSTITUTION:A clock switching circuit is equipped with AND circuit 9 and 14 and an OR circuit 10 and constituted by providing NOT circuits 6, 11, and 15 and flip-flops (FF) 7 and 8, 12 and 13, and 16. Then, the FF 16 synchronizes a clock switching signal C with clocks A and B, the FFs 7 and 8 delay pulses of the clocks A by two clocks at the time of switching the clock B to the clock A, and the FFs 12 and 13 delays pulses of the clock B by two clocks at the time of switching the clock A to the clock B. Then, when the asynchronous clocks A and B are alternated, short-period pulses are prevented from being generated.</p> |
