| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a metastability preventing synchronization circuit that can perform synchronization and an accurate signal transfer independent of metastability even in the event of an asynchronous transfer between clocks of the same frequency.SOLUTION: The metastability preventing synchronization circuit includes: a transfer duplication circuit 130 for dividing an input signal 130c into two systems adapted for an asynchronous transfer by clock signals 110a, 120a having the same frequency and different phases, and transferring the two systems synchronously; a pair of metastability detection circuits 140 for individually receiving transferred synchronization output signals 130a, 130b of the two systems output from the circuit 130, respectively, and outputting detection signals 140a, 140c indicating results of detection of metastability; and a transfer selection circuit 150 for selecting one of the signals 130a, 130b of the two systems in which no metastability is detected, to be a transfer output as a synchronization output signal 150a on the basis of the signals 140a, 140c from the pair of circuits 140.</p> |
