Digital Logic
Carry
The output generated when the sum of binary digits exceeds the column's capacity, propagating to the next column.
Detailed Explanation
In binary addition, when two 1s are added (1+1=10), the result is 0 with a carry of 1 to the next position. Full adders have a carry-in and carry-out, enabling multi-bit addition by chaining.
Carry propagation delay limits adder speed—in a ripple-carry adder, the final sum depends on carries rippling through all stages. Carry-lookahead logic computes carries in parallel using generate (G = A AND B) and propagate (P = A XOR B) signals.