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Chapter 9. Normal Forms and Logic Design. 9.2 PNF and CNF Normal Forms 9.3 DNF Normal Form and Boolean Function 9.4 Logic Design PNF:Prenix Normal Form CNF:Conjunction Normal Form DNF:Disjunctive Normal Form. 9.2 PNF and CNF Normal Forms. Example PNF
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Chapter 9 Normal Formsand Logic Design
9.2PNF and CNF Normal Forms 9.3DNF Normal Form and Boolean Function 9.4Logic Design PNF:Prenix Normal Form CNF:Conjunction Normal Form DNF:Disjunctive Normal Form
Example PNF (1) x in P(x) and x in Q(x) are in different domains, i.e. two x’s are different local variable transform it to the following PNF:
Example Please transform x y ((z (P(x, z) Q(y, z))r R(x, y, r)) to PNF. Ans. It can be transformed to
Example CNF(Conjunction Normal Form) Ans. ci:clause pij:literal e. g.
Example DNF (Disjunctive Normal Form) Ans. e. g.
Example Transform proposition logic to DNF. Ans. Four useful rules:
Rule (2) is called Idempotent Law. Rule (3) is called Distributive Law. Rule (4) is called Demorgan Law.
Example1 LogicDesign for Full Adder. Ans. represents carry.
Two-bit adder module Extension: Fig.9.4.4 Logic design of X+Y
Example Gray code. Ans. Also called Reflected Code Two-bit Gray code: 0 0 0 1 1 1 1 0
Three-bit Gray code: Mirror 0 0 0 1 1 1 1 0 U 1 0 1 1 0 1 0 0 L
0U and 1L: 0 0 0 0 0 1 0 1 1 0 1 0 1 1 0 1 1 1 1 0 1 1 0 0 0U 1L
ExampleInteger to Gray code. … e.g. b=(01)2, we have g=(g1g0)=(01)