Circuits / Plexers
2-to-1 Multiplexer
Routes one of 2^S data inputs to the output based on the Select line: Y = (~S · D0) + (S · D1).
A 2-to-1 multiplexer selects between two data inputs (D0, D1).
The Select line S chooses which input routes to the output Y.
When S=0: Y = D0; when S=1: Y = D1.
Internally: Y = (~S · D0) + (S · D1) using two AND gates and an OR gate.
Tip: If Y is always 0, check that the final gate is OR, not AND.
01Z floatingE conflict (dashed)
| D0 | D1 | S | Y |
|---|---|---|---|
| 0 | 0 | 0 | 0 |
| 0 | 0 | 1 | 0 |
| 0 | 1 | 0 | 0 |
| 0 | 1 | 1 | 1 |
| 1 | 0 | 0 | 1 |
| 1 | 0 | 1 | 0 |
| 1 | 1 | 0 | 1 |
| 1 | 1 | 1 | 1 |