Decoders & Traffic Control

A decoder takes a binary address and activates exactly one output line, the one matching that address. Every other output stays 0.

• A 2-to-4 decoder: 2 address bits, 4 outputs.
• A 3-to-8 decoder: 3 address bits, 8 outputs.
• An $n$-to-$2^n$ decoder in general.