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Karnaugh map (K-map)

What is a K-map?

A Karnaugh map (K-map) is a visual method used to simplify the algebraic expressions in Boolean functions without having to resort to complex theorems or equation manipulations. A K-map can be thought of as a special version of a truth table that makes it easier to map out parameter values and arrive at a simplified Boolean expression.

What is SOP?

What is POS?

2-variable K-map sample

SOP

a/b01
b'b
0a'01
1a23

POS

a/b01
bb'
0a01
1a'23

3-variable K-map sample

SOP

a/bc00011110
b'c'b'cbcbc'
0a'0132
1a4576

POS

a/bc00011110
b+cb+c'b'+c'b'+c
0a0132
1a'4576

4-variable K-map sample

SOP

ab/cd00011110
c'd'c'dcdcd'
00a'b'0132
01a'b4576
11ab12131514
10ab'891110

POS

a/bc00011110
c+dc+d'c'+d'c'+d
00a+b0132
01a+b'4576
11a'+b'12131514
10a'+b891110

Truth table of min term and max term (2 variable)

abSOP (Min Term)POS (Max Term)
00a'b' (m0)a+b (M0)
01a'b (m1)a+b' (M1)
10ab' (m2)a'+b (M2)
11ab (m3)a'+b' (M3)

Truth table of min term and max term (3 variable)

abcSOP (Min Term)POS (Max Term)
000a'b'c' (m0)a+b+c (M0)
001a'b'c (m1)a+b+c' (M1)
010a'bc' (m2)a+b'+c (M2)
011a'bc (m3)a+b'+c' (M3)
100ab'c' (m4)a'+b+c (M4)
101ab'c (m5)a'+b+c' (M5)
110abc' (m6)a'+b'+c (M6)
111abc (m7)a'+b'+c' (M7)

Truth table of min term and max term (4 variable)

abcdSOP (Min Term)POS (Max Term)
0000a'b'c'd'
(m0)
a+b+c+d
(M0)
0001a'b'c'd
(m1)
a+b+c+d'
(M1)
0010a'b'cd'
(m2)
a+b+c'+d
(M2)
0011a'b'cd
(m3)
a+b+c'+d'
(M3)
0100a'bc'd'
(m4)
a+b'+c+d
(M4)
0101a'bc'd
(m5)
a+b'+c+d'
(M5)
0110a'bcd'
(m6)
a+b'+c'+d
(M6)
0111a'bcd
(m7)
a+b'+c'+d'
(M7)
1000ab'c'd'
(m8)
a'+b+c+d
(M8)
1001ab'c'd
(m9)
a'+b+c+d'
(M9)
1010ab'cd'
(m10)
a'+b+c'+d
(M10)
1011ab'cd
(m11)
a'+b+c'+d'
(M11)
1100abc'd'
(m12)
a'+b'+c+d
(M12)
1101abc'd
(m13)
a'+b'+c+d'
(M13)
1110abcd'
(m14)
a'+b'+c'+d
(M14)
1111abcd
(m15)
a'+b'+c'+d'
(M15)

Possible pairs and quads (4 variable)