Question

Design an XNOR gate with two inputs A and B using only NAND gates. Mention the expressions in terms of A & B at the output of each NAND gate in your circuit diagram.

Answer 1

expression for X NOR output $Z_{XNOR}$ is,

$Z_{XNOR}=(A.B)+(A'.B')\\$

using de-Morgan's law,

$Z_{XNOR}=((A'.B')'.(A.B)')'\\$

So NAND output is $Z_{NAND}$ is,

$Z_{NAND=}(A.B)'$

using these two following logic circuit diagram is implemented,