Karnaugh map decomposition

Thread Starter

transistortransistor

Joined Oct 9, 2013
11
Hello everyone,

I need to implement the following function:

f(A,B,C) = (sum of the miniterms 2,4,5,6)

I can only use 4 NAND gates with two inputs. A,B,C complement are not available.

The question suggests that I should use K-Map Decomposition.

My question is: how am I supposed to use this technique? should I magically know how each operation looks on a K-map and think of ways to gather them?
 

MrChips

Joined Oct 2, 2009
30,714
You are supposed to have been shown how to draw Karnaugh maps.

Draw a Karnaugh map for three variables A, B and C.

Show the minterms 2, 4, 5, and 6 on the map. Then we'll guide you from there.
 

t06afre

Joined May 11, 2009
5,934

Thread Starter

transistortransistor

Joined Oct 9, 2013
11
Hello MrChips, thanks for helping.

Anyway, I know how K-Maps works.



In this case, I would use 3 NAND's to get the "complement" of the variables + 3 NANDS to the products (BC, AC, AB) + 1 NAND with three inputs to get the final function.

But the question says that I need to use just 4 two input NAND.

And then it suggests K-Map decomposition.

Here a image of an example:



Thats why I said "guess". It's not guessing, but I would need to know beforehand how AND/ORS or any other operation look on K-MAP so I would be able to gather them and get my function.
 

WBahn

Joined Mar 31, 2012
29,979
Hello MrChips, thanks for helping.

Anyway, I know how K-Maps works.



In this case, I would use 3 NAND's to get the "complement" of the variables + 3 NANDS to the products (BC, AC, AB) + 1 NAND with three inputs to get the final function.

But the question says that I need to use just 4 two input NAND.

And then it suggests K-Map decomposition.

Here a image of an example:



Thats why I said "guess". It's not guessing, but I would need to know beforehand how AND/ORS or any other operation look on K-MAP so I would be able to gather them and get my function.
So what on earth is preventing you from drawing the K-Map for A AND B and/or A OR B and seeing what it looks like on a K-MAP?
 
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