Binary Addition Section 4.5
Binary Addition Example
Binary Addition (2)
Derivation of ∑ BA∑
Derivation of Carry Out Question: What primitive best implements C o ? Inputs: A, B Outputs: C o =A∙B BACoCo
Implementation of a Half-Adder
Limitation of a Half Adder A half-adder does not account for carry-in.
Truth Table for a Full Adder carry-in
Karnaugh Map For the Sum Bit
Karnaugh Map For the Carry-Out Bit
Implementation of a Full Adder (carry-in)
Four-Bit Adder C 4 is calculated last because it takes C 0 8 gates to reach C 4.
Alternative Naming Convention for the Full Adder
Hardware Simplification 2 gate delays for C 3 !
Four-bit adder with Carry Lookahead