Number Systems and Circuits for Addition – Binary Adders Lecture 6 Section 1.5 Fri, Jan 26, 2007
Binary Addition Addition of binary digits produces a sum bit and a carry bit. pqsumcarry
Binary Addition The sum bit is p q. The carry bit is p q.
Binary Adders A binary half-adder adds two bits and produces a sum bit and a carry bit. A binary full-adder adds two bits and a carry-in bit and produces a sum bit and a carry-out bit.
Binary Half-Adder Circuit Design circuits for p q and p q. Consolidate them into one circuit, if possible.
Binary Full-Adder Circuit InputOutput pqc-insc-out
Binary Full-Adder Circuit Use two half-adders to add the bits two at a time. Add p and q, producing s 1 and c 1. Add c-in and s 1, producing s and c 2. Add c 1 and c 2, producing c-out. c 1 c 2 produces c-out. Design the circuit.
Adding 4-Bit Numbers Design a circuit using four full adders to add two 4-bit binary numbers.