Gray To Binary

The circuit converts a 4-bit Gray code to 4-bit binary code. The most significant bit of a binary code is the same as the most significant bit of the corresponding Gray code. Thus, the most significant bit of the output is simply copied from input G3. For the other bits: Bit i of a binary code is 1 if bits i to n - 1, where n is the total number of bits and bit index i starts from 0 (the rightmost/LSB), of the corresponding Gray code contain an odd number of 1s. This is implemented using 2-, 3-, and 4-input XOR gates.