Mark S. Rasmussen
Feb 13

So what’s a multiplexer you ask? A multiplexer is an integrated circuit that takes a number of inputs and outputs a smaller number of outputs. In this case we’re aiming at creating a 4-to-1 multiplexer. As the name implies, it takes four inputs and outputs exactly one output, determined by a select input. Depending on the number of input lines, one or more select lines may be required. For 2n input lines, n select lines are needed. In hardware terms, this is basically the simplest of switches.