Question

Design an 8-to-1 line multiplexer using only 4-to-1 line multiplexers and 2-to-1
line multiplexers.
help plz

Answer 1

I think first, create a 2-to-1 multiplexer with logic gates, 2 inputs, and 1 output (don't get select functionality).

What relationship do you see with regard to number of inputs versus selection lines for the output?

The above is just to ensure you understand a multiplexor, if you already understand them well, then the exercise is decent review.

Answer 2

The 8-to-1 requires 8 inputs, 1 output. How can you accomodate 8 inputs with the constraints you have: 2-to-1 MX, and 4-to-1 MX ? This question conveniently uses numbers that are powers of two...

Once you have designed for the 8 inputs, you should then see how you can further design for generating only 1 output.

Answer 3

You would use two 4-1 multiplexers that would then feed their outputs in to a 2-1 multiplexers this should give the equivalent of a single 8+1

Answer 4

what is a multiplexer ?!