Adder Circuits (OCR A-Level Computer Science): Flashcards

Perform binary addition

Arithmetic Logic Units (ALUs)

Half adders and full adders

Two single-bit binary numbers

Cannot handle carry input

XOR gate ($A \oplus B$)

AND gate ($A \land B$)

Three (two data bits and a carry bit)

$A$, $B$, and $C_{in}$

$A \oplus B \oplus C_{in}$

$(A \land B) \lor (B \land C_{in}) \lor (A \land C_{in})$

Multi-bit binary addition

Two XOR gates

Two AND gates and one OR gate

Half lacks carry-in input, full has it