One of the alternate to getting the same output as an AND Gate, is to put together NOR gates. The operator for NOT gates is (A+B)'
, However there is a problem, I can't get the same output an AND gate would.
This image is from https://en.wikipedia.org/wiki/NOR_logic
So for example if we take:
A = 1
B = 0
, I would expect 0 as a result, but that does not seem to be the case here since,
= (1 NOR 0) NOR (1 NOR 0)
= (0) NOR (0)
= 1
What am I doing wrong?
There is indeed an error in your expression.
The key here is to see that the first two ports each take a pair of values that are duplicates. So we have
(A NOR A)
(B NOR B)
This evaluates a NOT operation, so we get:
(NOT A)
(NOT B)
These two are then the operands of the final NOR, giving the desired result.
For your example with A = 1
B = 0
:
(1 NOR 1) == 0
(0 NOR 0) == 1
And
0 NOR 1 == 0
A | B | A NOR A | B NOR B | (A NOR A) NOR (B NOR B) |
---|---|---|---|---|
0 | 0 | 1 | 1 | 0 |
0 | 1 | 1 | 0 | 0 |
1 | 0 | 0 | 1 | 0 |
1 | 1 | 0 | 0 | 1 |