Answer 6—The two flip-flops and two AND gates detect edges on the input signal synchronized to the input clock. On the rising edge, the counter value is captured in the upper latch and the counter is reset, so X represents the period of the input signal. On the falling edge, the counter value is captured in the lower latch, so Y represents the high time of the input signal and Y/X represents its duty cycle.

Contributor: David Tweed