Q.
Logic gates $X$ and $Y$ have the truth tables shown below:
$X$
$Y$
0
0
0
0
1
1
0
0
1
0
0
1
0
1
1
1
When the output of $X$ is connected to the input of $Y$, the resulting combination is equivalent to a single
| $X$ | $Y$ | |||
|---|---|---|---|---|
| 0 | 0 | 0 | 0 | 1 |
| 1 | 0 | 0 | 1 | 0 |
| 0 | 1 | 0 | ||
| 1 | 1 | 1 | ||
Semiconductor Electronics: Materials Devices and Simple Circuits
Solution:
The truth table of the resulting logic circuit by connecting $X$ to $Y$ is as follows
$P$
$Q$
$R$
$R$
0
0
0
1
1
0
0
1
0
1
0
1
1
1
1
0
Hence, from the truth table, the combination is equivalent to a single NAND gate.
(OR $X$ is an AND gate and $Y$ is a NOT gate, thus the combination is NOT AND gate, i.e., a NAND gate)
| $P$ | $Q$ | $R$ | $R$ |
|---|---|---|---|
| 0 | 0 | 0 | 1 |
| 1 | 0 | 0 | 1 |
| 0 | 1 | 0 | 1 |
| 1 | 1 | 1 | 0 |