• A decoder is a combinational circuit similar to an encoder, however it operates in the other direction. A decoder is a device that turns n lines of input into 2n lines of output and generates the original signal as output from the coded input signal.
• Because it provides a high output only when all inputs are high, an AND gate can be utilised as the basic decoding element.
• The reverse operation of the decoder is to recover the original information signal from the coded bits.

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