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

Ring Counter Time-Slot Multiplexer

MediumLogic CircuitBuild

Time-division multiplexing systems assign distinct time slots to multiple data streams over a single communication channel. A standard binary counter requires a 2-to-4 decoder to separate these channels. Using a ring counter for channel selection provides one-hot decoded outputs natively, generating mutually exclusive enable signals directly and eliminating the need for additional combinational logic.

Implement a 4-bit ring counter that directly controls a 4-to-1 multiplexer. On an active-high rst signal, the counter must initialize to Q0 = 1 with all other state bits at 0. On each rising edge of clk, the high bit shifts to the next position in a circular sequence. The output Y must route the input data line D corresponding to the currently active Q signal.

| Q3 | Q2 | Q1 | Q0 | Y | |------|------|------|------|-----| | 0 | 0 | 0 | 1 | D0| | 0 | 0 | 1 | 0 | D1| | 0 | 1 | 0 | 0 | D2| | 1 | 0 | 0 | 0 | D3|

Constraints

  • Use exactly four D flip-flops for the state machine.
  • Connect the flip-flop outputs directly to the multiplexer data path logic.
  • Do not use a binary counter or binary-to-decimal decoder.
  • Reset must be asynchronous and active-high.

Topics

MultiplexersCountersShift Registers

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