Parallel and serial adders

Parallel adders:

• These add two multi-bit numbers represented in binary form on the input pins.
• The sum can be initialised with a single carry bit on the 'CI' pin.
• A carry output pin 'C' shows the highest order bit of the sum. It can be connected to the carry input of another adder to add numbers with more bits than a single part can handle.

Serial adders

• The serial adder adds a pair of binary digits together with a carry bit from the previous addition. Each addition is triggered by a pulse on the clock input.
• The carry bit from the addition at the previous clock pulse can be set to zero with the carry reset pin 'R'.
• Some serial adders can optionally output the complement of the sum.

See also:

• Adders
• Logic family parts
• Simulation of Digital ICs