Encoder

Encoder is a kind of multiplexer having multiple outputs depending upon the number of input lines. Encoder has 2^n input lines and n output lines. The n output lines generate the binary information depending upon  2^n input lines.  Consider the example of 8-to-3 encoder which have eight input lines and three output lines. The truth table of the encoder is shown in figure.   The eight input lines would have 2^8 = 256 combinations. In this case only eight of all  256 combinations have the binary information the remaining
are  ‘don’t care’.  Figure shows the combination logic circuit of 8-to-3 encoder.

Encoder

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