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

4-Bit SISO: Basic Chain Construction

EasyLogic CircuitBuild

Delay lines, digital filters, and serial communication interfaces rely on passing data sequentially through a chain of registers. The serial-in, serial-out (SISO) shift register acts as a digital delay line by holding a signal for a precise number of clock cycles.

Construct a 4-bit SISO shift register using D flip-flops. Data enters at D_in and propagates through the chain on the rising edge of the clock. The output Q_out must reflect the value of D_in exactly four clock cycles later. Assume all flip-flops initialize to 0.

| Clock Cycle | D_in | Q_out | Internal State (Q0, Q1, Q2, Q3) | |-------------|--------|---------|---------------------------------| | 0 (Initial) | 1 | 0 | 0, 0, 0, 0 | | 1 | 0 | 0 | 1, 0, 0, 0 | | 2 | 1 | 0 | 0, 1, 0, 0 | | 3 | 1 | 0 | 1, 0, 1, 0 | | 4 | 0 | 1 | 1, 1, 0, 1 | | 5 | 0 | 0 | 0, 1, 1, 0 |

Constraints

  • Use exactly four D flip-flops.
  • Connect the clock input of every flip-flop to a single shared clock signal.
  • Do not use pre-packaged shift register components.

Topics

SequentialFlip-FlopsShift 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