Simplification
To get simpler expression for fewer logic gate.
-> Cheaper
Algebraic
Use theorems
Open ended requires skills
Aims:
- Reduce number of literals
- Reduce number of terms
Sometimes these conflict, reducing one does not mean reduce the other
Focus on reduce literals by using the laws.
K-Map
Easy to use
Limited to no more than 6 variables
But we need truth table:
Make it to a sum of products, find everything that includes the answer
1. For each 1 in kMap, draw the largest possible group in power of 2
Draw the prime implicants
2. Take all groups that cover unique 1
Take all Essential Prime implicant
3. For any remaining 1, not cover by groups
Choose the smallest collection of prime implicant for the rest that were not covered in 2
Reading it:
See the intersection
If everything is 1, it is just true
Generalised
Group 1 : 0 literals
Group 2: 1 Literals
Size X : log(2) X literals
[Practice Here : 1.16]
Terminology
Implicant:
A produce term that could be use to cover several minterms of the function
-> The 1 in the boxes
Prime Implicant:
Maximal Possible implicate for a group of minterms
Essential Prime Implicant:
Prime implicant that contains 1 or more unique minterm
Prime implicant that contains 1 or more unique minterm
POS:
Find the F prime
=> Flip all the 0 and 1 from the original k-map
We use this to get the demorgon rule
(Or just do kmap on the 0s for original k-map if we are good)
5 Variable k map
6 variable K map
Don't care condition
The output can be 1 or 0.
e.g ABCD represents a digit, counts whether there are even numbers of 1 in the binary representation
Use x to indicate a don't care condition.
These don't care condition can be use to simplify the expression easily.
Use sumD(10,11,12,13) to show the dont care.