Answer:
A decoder is a circuit which has n inputs and 2n outputs, and outputs 1 on the wire corresponding to the binary number represented by the inputs. For example, a 2-4 decoder might be drawn like this:
and its truth table (again, really four truth tables, one for each output) is:
i1 Â i0 Â d3 Â d2 Â d1 Â d0
0 0 0 0 0 1
0 1 0 0 1 0
1 0 0 1 0 0
1 1 1 0 0 0
Explanation:
The following circuit generates all four minterms from two inputs, and implements the 2-4 decoder.
