What is the difference between Decoder and Demultiplexer in Computer Architecture?

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A decoder is a combinational logic circuit that converts a code into a set of signals. A decoder circuit does accurately the reversal of encoding. It has several inputs and outputs, and it is generally used to modify coded inputs into coded outputs supported both of them are diverse from each other.

In simple methods, it is a device that interprets encoded data or information into its initial format. It decodes encoded information. Therefore, the input code usually has fewer bits than the bits in the output code. A decoder is used in the client interface in various output devices including monitors, printers, calculators, DVD players, etc.


A circuit that makes data on an individual line and sends the data on any of the 2 n possible output lines is known as a demultiplexer. Hence, a demultiplexer is known as a single-input multiple-output switch. The values of n selection lines rule the selection of a determined output line.

A demultiplexer is the reverse process of the multiplexer. This is a process of reconverting a signal including digital or analog signal flows back to the initial separate and independent signals.

The demultiplexer is only the reverse of the multiplexer, but it is not the opposite of the multiplexer. The opposite of multiplexer is known as inverse multiplexing, which divides one data stream into multiple associated data streams. The difference between inverse multiplexing and demultiplexing is, the output streams of demultiplexing are independent, whereas the output streams of inverse multiplexing are connected.

Let us see the comparison between Decoder and Demultiplexer

A decoder get a set of binary inputs and activates only the output that a complement to that input number.
A demultiplexer is a circuit that gets data on a single line and sends this data on one of several output lines.
It can be used for decoding the encoded input terminal.
It can be used for switching.
It receives n input lines and makes 2^n output lines, which is completely reversed of what an encoder does.
It sends information from one line to 2^n possible output lines, where the output line is decided by n select lines.
It is used in several applications including data demultiplexing, memory address decoding, etc.
It is primarily used in communication systems and networking solutions for security goals.
It has no selection lines.
An output line is decided by the cost of select lines.
Published on 23-Jul-2021 10:25:45