Prepared by: Careene McCallum-Rodney Multiplexor

Introduction A multiplexer or mux is a device that performs multiplexing. It selects one of many analog or digital input signals and outputs that into a single line. An electronic multiplexer makes it possible for several signals to share one expensive device or other resource, for example, one A/D converter or one communication line, instead of having one device per input signal.

Introduction A multiplexor is a selector. The purpose of the multiplexor is to select one of the inputs and output the value stored at its location.

Multiplexor’s inputs It has more than one inputs. The number inputs should amount to a power of two. Hence, you can have 2 inputs, 4 inputs, 8 inputs, 16 inputs, 32 inputs, and so on.

Multiplexor’s Input Each input will have a unique identifier. The number of bits for each input is based on the number of inputs. For example, 8 inputs is 2 3, therefore each input will have 3 bits making up its identifier.

Multiplexor’s Output Therefore, a multiplexor will have ONLY ONE OUTPUT.

Multiplexor’s Selectors To the side of the multiplexor is the selector. The selector will need to know the unique name of the input being selected. Hence, if each input has 2 bits for their unique identifier, then there will be 2 bits for the selector.

Quick Check S0S0 S1S1 S2S GBFAGBFA

Activity 1 - Draw a 4 – 1 bit MUX

Activity 1 - Draw a 2 – 1 bit MUX

Activity 1 - Draw a 16 – 1 bit MUX