(Solved): 3. The incrementer and decrementer can be combined into a single circuit by adding one more gate. Wh ...

3. The incrementer and decrementer can be combined into a single circuit by adding one more gate. When computing the carry/borrow for decrementing, each bit is flipped. This is accomplished by using an XOR gate with the decrement condition as an input. If decrement is 1 , the input bit is flipped. To increment, the decrement input is set to 0 and the bit passes through the XOR gate unchanged. Build a 4-bit incrementer/decrementer. What is its critical path? Assume each two-input gate has a propagation delay of \( d \), what is the propagation delay of the inc/dec circuit? If it were a 16-bit inc/dec circuit, what would be its propagation delay?