Positive edge–triggered D-type flip-flop (OCR A-Level CS). D is randomly generated; Q and ¬Q change only at the exact rising edge of the clock. The red dashed line sweeps smoothly across time.
• On each rising edge of the clock (0 → 1), the flip-flop copies D into Q. • Between rising edges, Q holds its stored value. • ¬Q is always the inverse of Q.