ABSTRACT
A decoder is a circuit that changes a code into a set of signals. It is called a decoder because it does the reverse of encoding. A common type of decoder is the line decoder, which takes an m-bit binary input datum and decodes it into data lines. When the decoder is enabled, then the output line whose index is equal to the value of the input binary data is asserted (set to 1 for active high), while the rest of the output lines are de-asserted (set to 0 for active high). When the decoder is disabled with active high enable input set to 0, all the output lines are de-asserted.
