In my last blog I have given you some examples, solving Sum of Product (SOP) and Product of Sum (POS) using Karnaugh Map. Today we will solving the same using Quine-McCluskey Method (Tabulation Method) Example 1: Simplify the following using Quine-McCluskey Method (Tabulation Method) f(A,B,C) = Σm(0,1,4,5,6) + Σd(6) Example 1: f(A,B,C) = Σm(0,1,4,5,6) + Σd(6) Terms given that includes the don't care option | |
0 | 000 |
1 | 001 |
4 | 100 |
5 | 101 |
6 | 110 |
7 | 111 |
Repetition of 1's is the basis of grouping. |
Group 1 | |||
0 | 000 | Weight = 0 [Group with zero : 1's] | |
Group2 | |||
1 | 001 | Weight = 1[Group with one : 1's] | |
4 | 100 | ||
Group 3 | |||
5 | 101 | Weight = 2 [Group with two : 1's] | |
6 | 110 | ||
Group 4 | |||
7 | 111 | Weight = 3 [Group with three : 1's] | |
Combine a suitable pair to form Column 2, pair can be formed between adjacent group basis of difference. Put a hyphen(-) to indicate difference between the terms. Forming column three will be on the basis of adjacent pairs that having a hyphen (-) in the identical place. Those terms is used should be marked, here to mark, I used √.
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Column I (Number of 1' Implicants)
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Column II (Size 2)
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Column III (Size 4)
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Group1 | ||||||
0 | 000 √ | (0,1) √ | 00- | (0,1,4,5) | -0- | |
(0,4) √ | -00 | (0,4,1,5) | -0- | |||
Group 2 | ||||||
1 | 001 √ | (1,5) √ | -01 | |||
4 | 100 √ | (4,5) √ | 10- | (4,5,6,7) | 1-- | |
(4,6) (not used) | 1-0 | |||||
Group 3 | ||||||
5 6 | 101√ 110 √ | (5,7) (6,7) | 1-1 11- | |||
Group 4 | ||||||
7 | 111 √ |
Rows = prime implicants and columns = ON-set elements place an "X", if ON-set element is covered by the prime implicant.Make the following chart using the given terms but do not use the don't care options (cell 7). Also omit the if any duplicate entries like (0,1,4,5) (0,4,1,5).
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0 | 1 | 4 | 5 | 6 | |||
-0- | B' | (0,1,4,5) | X | X | X | X | |
-0- | B' | (0,4,1,5) | X | X | X | X | |
1-- | A | (4,5,6,7) | X | X | X | ||
1- 0 | AC' | (4,6) | X | X |
After removing duplicate entries we get the following. Now columns 0 and 1 also to be removed as these column has a single X, it has the implicant associated with the row (+) is essential. It must appear in minimum cover.
(**) columns has only one X and row to be covered is (0,1,4,5) = B'
(*) omit 0,1,4,5 as it is already covered.
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0 (**) | 1 (**) | 4 | 5 | 6 | |||
-0- | B' | (0,1,4,5) + | X (*) | X (*) | X (*) | X (*) | |
1-- | A | (4,5,6,7) | X | X | X | ||
1- 0 | AC' | (4,6) | X | X |
Eliminate all columns covered by essential primes (4,5). Find minimum set of rows that cover the remaining columns (4,5,6,7) = A. f(A,B,C) = Σm(0,1,4,5,6) + Σd(6) = A + B'. |
Example 2: Simplify the following using Quine-McCluskey Method (Tabulation Method) |
f(A,B,C,D) = Σm(0,2,8,10,12,13,14,15) + Σd(5,7) |
Terms given : | |
0 | 0000 |
2 | 0010 |
5 | 0101 |
7 | 0111 |
8 | 1000 |
10 | 1010 |
12 | 1100 |
13 | 1101 |
14 | 1110 |
Rewriting in the List basis of weight of 1's | |
0 | 0000 |
2 | 0010 |
8 | 1000 |
5 | 0101 |
10 | 1010 |
12 | 1100 |
7 | 0111 |
13 | 1101 |
14 | 1110 |
15 | 1111 |
Group it basis of repetition of 1's | |||
Group 1 | |||
0 | 0000 | Weight = 0[Group with zero : 1's] | |
Group2 | |||
2 | 0010 | Weight = 1[Group with one : 1's] | |
8 | 1000 | ||
Group 3 | |||
5 | 0101 | Weight = 2 [Group with two : 1's] | |
10 | 1010 | ||
12 | 1100 | ||
Group 4 | |||
7 | 0111 | Weight = 3[Group with three : 1's] | |
13 | 1101 | ||
14 | 1110 | ||
Group 5 | |||
15 | 1111 | Weight = 4[Group with three : 1's] | |
Combine a suitable pair to form Column 2, pair can be formed between adjacent group basis of difference. Put a hyphen(-) that indicate difference between the terms. Column three only can be formed on the basis of the pairs having a hyphen (-) in the identical place. Those terms already combined should be marked, here to mark, I used √.
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Column I (Number of 1' Implicants) | Column II (Size 2) | Column III (Size 4) |
Group1 | ||||||
0 | 0000 √ | (0,2) √ | 00-0 | (0,2,8,10) | -0-0 | |
(0,8) √ | -000 | (0,8,2,10) | -0-0 | |||
Group 2 | ||||||
2 | 0010 | (2,10) √ | -010 | (8,10,12,14) | 1--0 | |
8 | 1000 √ | (8,10) √ | 10-0 | (8,12,10,14) | 1--0 | |
(8,12) √ | 1-00 | |||||
Group 3 | ||||||
5 | 0101 √ | (5,7) √ | 01-1 | (5,7,13,15) | -1-1 | |
0 | 1010 √ | (5,13) √ | -101 | (5,13,7,15) | -1-1 | |
12 | 1100 √ | (10,14) √ | 1-10 | (12,13,14,15) | 11-- | |
(12,13) √ | 110- | (12,14,13,15) | 11-- | |||
(12,14) √ | 11-0 | |||||
Group 4 | ||||||
7 | 0111 √ | (7,15) √ | -111 | |||
13 | 1101 √ | (13,15) √ | 11-1 | |||
14 | 1110 √ | (14,15) √ | 111- | |||
Group 5 | ||||||
15 | 1111 √ | |||||
Rows = prime implicants and columns = ON-set elements, place an "X", if ON-set element is covered by the prime implicant. Make the following chart using the given terms but do not use the don't care options. Also omit the duplicate entries such like (0,2,8,10) and (0,8,2,10), (8,10,12,14) and .(8,12,10,14), (5,7,13,15) and (5,13,7,15), (12,13,14,15) and (12,14,13,15).
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0 | 2 | 8 | 10 | 12 | 13 | 14 | 15 | |||
B'D' | -0-0 | (0,2,8,10) | X | X | X | X | ||||
B'D' | -0-0 | (0,8,2,10) | X | X | X | X | ||||
AD' | 1--0 | (8,10,12,14) | X | X | X | X | ||||
AD' | 1--0 | (8,12,10,14) | X | X | X | X | ||||
BD | -1-1 | (5,7,13,15) | X | X | ||||||
BD | -1-1 | (5,13,7,15) | X | X | ||||||
A | 11-- | (12,13,14,15) | X | X | X | X | ||||
AB | 11-- | (12,14,13,15) | X | X | X | X | ||||
After removing duplicate entries we get the following. Now columns 0 and 2 column has a single X, the implicant associated with the row (+) is essential. It must appear in minimum cover. (**) columns has only one X and row to be covered is (0,2,8,10) = B'.D'.
* omit 0,2,8,10 as it has already covered.
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0 ** | 2 ** | 8 | 10 | 12 | 13 | 14 | 15 | |||
B'D' | -0-0 | (0,2,8,10) + | X * | X * | X * | X * | ||||
AD' | 1--0 | (8,10,12,14) | X | X | X | X | ||||
BD | -1-1 | (5,7,13,15) | X | X | ||||||
AB | 11-- | (12,13,14,15) | X | X | X | X | ||||
Eliminate all columns covered by essential primes (8,10). Find minimum set of rows that cover the remaining columns (5,7,13,15) and (12,13,14,15) =BD and AB. Therefore, from given minterms f(A,B,C,D) = Σm(0,2,8,10,12,13,14,15) + Σd(5,7) = AB + B'D' + BD To give you these two examples I have to spent a couple of hours when easily could have solve it within couple of minutes using Karnaugh Map. Often students ask me why to learn this when it is taken more time than the other easier process, frankly I have no idea. My next target will be booth algorithm and hope will post in time. !!!For those students who are going to appear in I.C.S.E. and I.Sc., best wishes for your exam.!!! |