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

D to SR Conversion: SR Flip-Flop from DFF

MediumLogic CircuitBuild

ASIC libraries often contain a limited set of sequential primitives. Synthesizing arbitrary state elements requires mapping desired behavior onto available flip-flops using excitation tables.

Implement a positive-edge-triggered D flip-flop using a single SR flip-flop and basic combinational logic. The circuit must sample the D input on the rising edge of clk and update the output Q.

| D | Q (current) | Q (next) | |-----|---------------|------------| | 0 | 0 | 0 | | 0 | 1 | 0 | | 1 | 0 | 1 | | 1 | 1 | 1 |

Constraints

  • Use exactly one SR flip-flop.
  • Use only combinational logic to drive the S and R inputs.
  • Do not use any D flip-flops.
  • The combinational logic must structurally guarantee that the forbidden state S = 1 and R = 1 is never reached.

Topics

Sequential LogicFlip-FlopsState Conversion

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