Sum of Products Section 2.7
Home Alarm Example (Truth Table) (Boolean Algebra)
Truth Table Definition: Alarm Response (AR) Sound Alarm→AR=1 Else: AR=0 (Truth Table)
Determine a Boolean Function from a Truth Table When is AR=1? 𝑃 𝐷 𝑊1 𝑊2 𝑃 𝐷𝑊1 𝑊2 What about these terms?
Exercise Use the following properties to simplify the home alarm logic: X ∙(Y+Z)=X ∙ Y+X ∙ Z 𝑋+ 𝑋 =1
W1=0V, P=W2=5V
P=W1=5V, W2=0 V
Minterm/maxterm
Minterms Procedure: Form a minterm for each combination of the variables that produces a 1 OR all the minterms.
Example 𝑓1= 𝑥 𝑦 𝑧+𝑥 𝑦 𝑧 +𝑥𝑦𝑧
f1 Form a maxterm for each term that produces a 0 AND all of those terms 𝑓1=(𝑥+𝑦+𝑧)(𝑥+ 𝑦 +𝑧) (𝑥+ 𝑦 + 𝑧 )( 𝑥 +𝑦+ 𝑧 )( 𝑥 + 𝑦 +𝑧) Interpretation: Each maxterm can zero out f1
Standard Forms The minterm representation leads to Sum of Products implementation The maxterm representation leads to Products of Sums implementation
Exercise F2 A B C 1
F1 A B C 1