Selecting & Comparing

Multiplexers and comparators

An interactive lesson with 7 steps, about 6 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• A multiplexer uses select bits to choose an input; n select bits choose among 2ⁿ inputs.
• XNOR detects equal bits; AND-ing them tests whether numbers are equal.
• ALUs compute many results in parallel and select one.

Steps

1. A railway junction for data
2. Route the signal
3. Eight inputs
4. Are two numbers equal?
5. Equal or not?
6. Inside a processor
7. Comparing big numbers