# Simple logic design-what is minterm

Discussion in 'Homework Help' started by athulascc, Mar 7, 2015.

1. ### athulascc Thread Starter Member

Aug 15, 2014
88
1
here is the image of my assignment
I have knowleadge to do it.
but according to my knowledge minterm is P.Q.R.S here,
but If I fill table in that manner minterm value always 0 or 1
is it correct ; there is problem if it is only 0 or 1

Mar 31, 2012
18,087
4,917
3. ### athulascc Thread Starter Member

Aug 15, 2014
88
1
but according to that minterm value is always 0 or 1.

so there is problem with given design.
my SID is 5460449

but they have told that function give output=1 when minterm value = prime number
so how it happens? both 0 & 1 are prime

4. ### WBahn Moderator

Mar 31, 2012
18,087
4,917
Look at Table #2 in that link I provided. The minterm value is the number in the left column.

The problem statement has a hole in it. It doesn't say what the output should be if the minterm value doesn't match any of the digits in your SID and it is not prime. Is this a '0' or is it a 'don't care'?

5. ### athulascc Thread Starter Member

Aug 15, 2014
88
1
I thought if SID digits match with minterm and not prime, output is 0. am I correct?

6. ### athulascc Thread Starter Member

Aug 15, 2014
88
1
here I filled according to instructions.
I think I am correct

7. ### WBahn Moderator

Mar 31, 2012
18,087
4,917
The problem explicitly states that if the minterm matches one of the digits in your SID, then the output is a "don't care". That is different than saying that it is a 0 -- it can be either and it doesn't matter which it is.

The problem does not specify what it should output if the minterm does not match one of the digits in your SID and it is not prime. It is not unreasonable to infer that it should be 0 in that case, but the problem does not specify it and, in general, unspecified conditions are treated as "don't cares" -- though it is also, in general, a poor specification that fails to specify all possibilities in some way.

8. ### WBahn Moderator

Mar 31, 2012
18,087
4,917
Yes, that looks correct.