Topic: Digital Circuits
Assuming that only the X and Y logic inputs are available and their complements X_bar and Y_bar are not available, what is the minimum number of two-input NAND gates required to implement X XOR Y?
- A. 2
- B. 3
- C. 4
- D. 5
Answer: C. 4
Explanation: To implement an XOR gate using only two-input NAND gates without inverted inputs readily available, a minimum of 4 NAND gates are required. The configuration uses one NAND gate for (X NAND Y), and then uses its output as inputs to two subsequent NAND gates along with X and Y respectively, feeding into a final fourth NAND gate.