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- 22nd March 2006, 19:13 #1

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## Interview Q

hi,

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

ple reply soon its urgent.

thanks in advance.

bye,

Prasad

- 22nd March 2006, 19:13

- 23rd March 2006, 08:49 #2

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## 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

- 23rd March 2006, 08:49

- 23rd March 2006, 10:57 #3

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## Re: Interview Q

Check the document

- 23rd March 2006, 10:57

- 24th March 2006, 10:37 #4

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## 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.

- 25th March 2006, 13:23 #5

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## Re: Interview Q

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

- 25th March 2006, 13:23

- 5th March 2007, 12:43 #6

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## 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.

- 5th March 2007, 12:57 #7

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## 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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