How to implement 4:1 mux and 2:1 mux as a Nor gate?

1. Interview Q

hi,

hw to implement 4:1 mux and 2:1 mux as Nor gate?

bye,

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2. Re: Interview Q

2 x 1 MUX, make the equation first:

O = (EN & A) | (ENb & B)

then make it logic gates

finally replace to NOR gates

3. Re: Interview Q

Check the document

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4. Re: Interview Q

For a 2 input nor gate,there are 4 possible combinations,so we can implement it using 4 x 1 multiplexer.The two inputs A and B are given to the mux as selection inputs and keeping enable signal high.

Now for 2 input nor gate the output will be 1 when all inputs are 0.,thus we will connect Vcc to I0 and ground to I1,I2 and I3.

5. Re: Interview Q

I have drawn the diagram for nor gate by using 2 X 1 MUX

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6. Re: Interview Q

hi,

Nor using 4×1 mux, suppose A,B are select lines. Y is output.
I0,I1,I2,I3 are input to mux.
Give VDD to I0,
GND to I1,I2,I3.

Nor using 2×1 mux,
I0,I1 are input to mux,
Take A as select line.
Give complement of B to I0 input of Mux.
Gnd to I1 input of Mux.

Checkfunctionality.

Hop u understand.

If u hav any doubts tell me.

7. Interview Q

Hi p_shinde
Look what a nor gate does.Assume A and B are inputs.
If B zero it passes the (A complement) to output.
if B is one then output is '0'.
Now connect B to select
A' to LSB input
and logic 1 to MSB input

Regards
tronix

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