一种稀疏树加法器及结构设计

提出了一种稀疏树加法器，该加法器基于并行前缀加法器，以预处理和后处理阶段的面积和延迟换取并行前缀进位阶段的面积和延迟，可针对大多数并行前缀加法器进行改进，在较长操作数相加时可节省面积同时减小关键路径延迟。以几种并行前缀加法器Sldarisky、Brent—Kung、Kogge—Stone和Han—Carlson为例，对他们的面积和延迟进行了理论分析。在本文的最后用硬件描述语言实现了Sklansky加法器。

A Kind of Sparse Tree Adder and its Structure Design

This paper proposed a Kind of Sparse Tree Adder which is based on the parallel prefix adder and exchanges the area and delay increasing in the preprocess and post-process stage for the area and delay saving in the parallel prefix carry stage. When the operand is long there exists an alternative selection to almost all of the parallel prefix adder, to save the area and to lessen the critical path delay. Also, the area consume and delay of Sklansky, Brent-Kung , Kogge-stone and Han-Carlson parallel prefix adder are analysed in theory. The sparse tree adder and the parallel prefix adder is implemented and simulated.