Implementing F(A,B,C)=Σm(0,1,2,3,7)F(A,B,C)=\Sigma m(0,1,2,3,7) (K-Map + Logic-Gate SOP)

Implementing F(A,B,C)=Σm(0,1,2,3,7)F(A,B,C)=\Sigma m(0,1,2,3,7) (K-Map + Logic-Gate SOP)

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Nov 4, 2026

Karnaugh Map (K-Map) Simplification for Boolean Functions

To implement the Boolean function F(A,B,C)=Σm(0,1,2,3,7),F(A,B,C)=\Sigma m(0,1,2,3,7), we convert its minterm set into a simplified Sum-of-Products (SOP) expression and then map that SOP to logic gates.

We first adopt the standard minterm indexing for three variables where the index corresponds to (A,B,C)(A,B,C) interpreted as a binary number. This is consistent with common textbook/K-map conventions for 3-variable problems 2.

Key objects:

  • SOP form: F=(AND terms)  ORed togetherF = \text{(AND terms)} \;\text{ORed together}
  • Karnaugh map (K-map): visual grouping of 1s
  • Implicant: each grouped 1s block becomes an AND term

Footnotes

  1. https://en.wikipedia.org/wiki/Boolean_function - Overview of Boolean functions, minterms/maxterms concept, and standard representations. ↩

  2. https://en.wikipedia.org/wiki/Karnaugh_map - Karnaugh map method for simplifying SOP/POS by grouping 1s into powers of two. ↩

1) Build the minterms table (using the 3-variable indexing)

For A,B,CA,B,C, minterm index mm corresponds to the binary value (A,B,C)(A,B,C) (with AA as MSB). Thus:

Minterm(A,B,C)(A,B,C)F=1F=1?
m0m0(0,0,0)(0,0,0)1
m1m1(0,0,1)(0,0,1)1
m2m2(0,1,0)(0,1,0)1
m3m3(0,1,1)(0,1,1)1
m7m7(1,1,1)(1,1,1)1

So FF is 1 for all cases where A=0A=0 (that’s m0,m1,m2,m3m0,m1,m2,m3), and it is also 1 for (A,B,C)=(1,1,1)(A,B,C)=(1,1,1) (m7m7). This interpretation drives the simplification 2.

Mermaid view of what we know:

Footnotes

  1. https://en.wikipedia.org/wiki/Boolean_function - Overview of Boolean functions, minterms/maxterms concept, and standard representations. ↩

  2. https://en.wikipedia.org/wiki/Boolean_algebra - Boolean algebra identities and conventions for NOT/AND/OR and simplification. ↩

K-Map to simplified SOP

  1. 1
    Step 1

    Create a 3-variable K-map for A,B,CA,B,C and mark 11 cells at minterms m(0,1,2,3,7)m(0,1,2,3,7).

  2. 2
    Step 2

    Group m0,m1,m2,m3m0,m1,m2,m3 together as a block of 4 (a power of two). This yields one simplified implicant.

  3. 3
    Step 3

    In the A=0A=0 group, AA is always 0, so the term becomes A′A'.

  4. 4
    Step 4

    Since m7m7 is not covered by a larger group with other 1s (in the given set), cover it with the smallest valid group (a single cell).

  5. 5
    Step 5

    At m7m7, (A,B,C)=(1,1,1)(A,B,C)=(1,1,1) so the term is A⋅B⋅CA\cdot B\cdot C.

  6. 6
    Step 6

    Combine terms: F=A′+ABC.F = A' + ABC. Then verify by checking that all specified minterms evaluate to 1 and the others to 0.

2) Simplified Boolean function

From the K-map grouping described above, the simplified SOP is:

F(A,B,C)=A′+ABC.F(A,B,C)=A' + ABC.

Equivalently, using A′A' means NOT-AA, and ABCABC is an AND of all three variables. This kind of simplification via K-map grouping is a standard procedure for minimizing Boolean logic 2.

Implementation-ready form

  • Complement (NOT): A′A'
  • Conjunction (AND): ABCABC
  • Disjunction (OR): A′+ABCA' + ABC

Footnotes

  1. https://en.wikipedia.org/wiki/Karnaugh_map - Karnaugh map method for simplifying SOP/POS by grouping 1s into powers of two. ↩

  2. https://en.wikipedia.org/wiki/Boolean_algebra - Boolean algebra identities and conventions for NOT/AND/OR and simplification. ↩

Gate mapping shortcut

Once you have F=A′+ABCF=A'+ABC, build A′A' with one NOT gate, build ABCABC with 2 AND gates (or a 3-input AND), then OR them.

Be careful with minterm indexing convention

The result depends on the standard mapping of mm to (A,B,C)(A,B,C) bits. Most K-map references assume mm is the binary value of (A,B,C)(A,B,C) with AA as MSB; using a different convention changes which cell is m7m7.

3) Implementation using basic logic gates

We implement F=A′+ABCF=A' + ABC:

  1. Compute A′A' using a NOT gate on input AA.
  2. Compute ABCABC:
    • AND AA and BB, then AND the result with CC (or use a 3-input AND).
  3. OR the two signals: A′A' OR (ABC)(ABC).

Mermaid logic diagram:

From minterms to hardware

Interpret Σm

Step 1

Map each minterm index mm to a specific input combination (A,B,C)(A,B,C)."

K-map placement

Step 2

Mark all 11 cells at m=0,1,2,3,7m=0,1,2,3,7."

Group 1s

Step 3

Create the largest power-of-two group(s): 4-cell group for A=0A=0; single for m7m7."

Extract implicants

Step 4

4-cell group → A′A', single cell → ABCABC."

Build gates

Step 5

NOT for A′A', AND for ABCABC, OR to combine."

Minterms covered by each implicant

Shows which 1-cells are explained by the simplified terms.

Quick verification and edge cases

Knowledge Check

Question 1 of 4
Q1Single choice

Given F(A,B,C)=Σm(0,1,2,3,7)F(A,B,C)=\Sigma m(0,1,2,3,7) with the standard 3-variable minterm indexing, which simplified SOP matches the K-map result?