# multiplexer

Discussion in 'Homework Help' started by kiuhnmgtrdcv, Dec 19, 2009.

1. ### kiuhnmgtrdcv Thread Starter New Member

Dec 19, 2009
2
0
hello everyone
iam very new into digital logic
i have a question
please look at the below picture

i think a lot but i couldn't find out How I0 and I1 calculate through Karnaugh Map?
when I calculate with Karnaugh Map the answer doesn't match with given answer I0 and I1 ?

2. ### zeelangah New Member

Dec 17, 2009
2
0
if u want to solve it using k-map then u should consider POS form for mapping bc no. of Zero's is less than no. of one's so u can easily find the solution

3. ### kiuhnmgtrdcv Thread Starter New Member

Dec 19, 2009
2
0
I also use POS form but when i compare I0 and I1 with this image

i can't figure out anything
I0 and I1 should be
I0=b xor c
I1=b' + c'
but according to the karnough map
X=(A+B+C)(B'+C')
--------------------
Where is my mistake?

4. ### Ratch New Member

Mar 20, 2007
1,068
3
kiuhnmgtrdcv,

How come you don't capitalize the word at the beginning of a sentence, but do capitalize other words within the sentence even when they shouldn't be? Anyway, attachment 14559 looks correct to me. I can't understand attachment 14560. What does the vertical line before a variable mean? How about using notatiion like (A'+B)C so that everyone can understand it.

So, referencing attachment 14599, when A is zero, only I0 is fed into outout F. So looking at the top row of the K-map where A is always 0, we see only minterms 1 and 2. Those two minterms represent a exclusive OR which I see attached to I0. So far so good. Now when A is 1, only I1 is fed into output F. So, looking at the bottom row of the K-map where A is always 1, we see minterms 4,5,6. Those three minterms represent B'+C', which I see attached to I1. So what is your question?

Ratch