CodiodeCodiode
Home
Problem Solving
Skill Tracks
My Assignments
Contests
Leaderboard
Community
Settings
Codiode/Problems/Sequential Logic

Two DFFs in Series: Pipeline Latency

MediumLogic CircuitTiming Diagram

Two positive-edge-triggered D flip-flops are connected in series to form a two-stage pipeline where each flip-flop captures its input on the LOW-to-HIGH transition of the shared clock.

Four signals are shown: CLK (clock, period 2), D1 (input to the first stage), Q1 (output of the first stage, initially 0), and Q2 (output of the second stage, initially 0).

Trace Q1 and Q2 across all 12 time steps.

Constraints

  • The output Q1 updates to match D1 only at the rising edge of CLK.
  • The output Q2 updates to match the pre-edge value of Q1 only at the rising edge of CLK.
  • Changes to D1 between clock edges do not affect the outputs until the next rising edge.

Topics

pipelinetiming-diagramlatches-and-flip-flopslatency

Solve this problem

Place the gates, wire them up and watch the signals settle. Every submission runs on the same simulation engine that grades it.

This problem is part of Codiode Pro. The statement above is free to read.

Sign in to solveSee what Pro unlocks

The circuit builder and code editor need a desktop screen. On a phone, read the problem here and open it on a laptop to solve.

Related problems

  • 3-bit Ripple Counter from Toggle Flip-FlopsEasy
  • D Latch from a 2:1 MUXEasy
  • 2-bit Ring CounterEasy
  • T Flip-Flop from a D Flip-FlopEasy
  • Handshake Deadlock Due to Early ResetHard
  • Reconvergence of Individually Synchronized BitsHard
  • Debug: Asynchronous Clear GlitchHard
  • Clock Gate Enable Crossing DomainsHard

Browse all problems · Learning tracks