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In this article, you will find out what the purpose of adder is. There is a certain reference value, there are friends in need can refer to, I hope to help you.

The purpose of the adder using carry lookahead is to speed up the transfer of carry signals. Carry lookahead is the carry produced simultaneously by high order carry and low order carry, while carry lookahead adder is independent of each other, only related to input data A, B and C_in, and the carry cascade between stages is propagated to remove, so that the delay caused by carry can be reduced and the carry signal can be transmitted faster.

The purpose of the adder using carry lookahead is to "speed up the transfer of carry signals."

A carry chain is a logic circuit that transmits carry. Carry lookahead is a carry produced simultaneously by high and low carry. There are two kinds of lookahead carry, one is intra-group parallel, inter-group serial carry chain, the other is intra-group parallel, inter-group parallel carry chain, also known as parallel carry.

Carry lookahead adder, the carry of each stage is independent of each other, only related to input data A, B and C_in, the carry cascade between stages is propagated to remove, so that the delay caused by carry can be reduced. Each equation corresponds to a circuit with only three delays, the first delay corresponding to the carry-generated signal and the carry-passed signal, and the last two delays corresponding to the sum of the products above. Adders implemented in this way are called carry-ahead adders. Because the carry is generated in parallel, it is a parallel carry adder.

The carry-look-ahead adder avoids the carry-delay of the ripple carry-adder and increases the speed. Although the carry-look-ahead part is increased, it still consumes less resources than the selective carry-look adder. The optimization design of basic unit circuit and its combination scheme and structure can further reduce resource (area) occupation, improve speed and reduce power consumption. Determining the optimized basic unit circuit and its combination scheme will provide a basis for the optimization of CLA structure design.

The above is a brief introduction to what the purpose of the adder is, of course, the detailed use of the above differences have to be used by everyone to understand. If you want to know more, welcome to pay attention to the industry information channel!

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