Multiply-add method and multiply-add apparatus

Abstract

The invention disclose a multiply-add method and multiply-add apparatus, the method comprises the following steps: (1) a multiplier generates a plurality of control signals through a Bush coding logical unit, a multiplicand serves as the input of a partial product generating logical unit, and a partial product is generated; (2) an addend obtains a lower-order intercepting part, an intermediate part and a higher-order intercepting part through an addend partitioning logical unit; the lower-order intercepting part, the intermediate part and the partial product serve as the input of an improved Wallace tree unit, the obtained result serves as the input of an adder, and a lower-order result and a control signal are generated; 3 the higher-order intercepting part obtains a higher-order result through a higher-order forecasting logical unit; and (4) the lower-order result and the higher-order result obtains a final result through a matching logical unit. The multiply-add apparatus comprise the Bush coding logical unit, the partial product generating logical unit, the addend partitioning logical unit, the adder, the higher-order forecasting logical unit, the improved Wallace tree unit and the matching logical unit. The invention has the advantages of simple and compact structure, low cost, quick arithmetic speed, stabilization, reliability, and the like.

Description

technical field [0001] The invention mainly relates to the field of multiply-add processors, in particular to a multiply-add method and a multiply-add device. Background technique [0002] The traditional multiplication and addition fusion is to put the addend as a partial product at the bottom of the Wallace tree of the multiplier. When performing a rectangular layout, using a traditional Wallace tree multiply-adder will result in a large waste of area. Mounir Bohsali (Many Boselli) and Michael Doan (Michel Doan) proposed a method to transform the traditional multiplier Wallace tree and obtain a new type of Wallace tree . Since the Wallace tree of the multiplier is relatively regular, it is easy to divide the Wallace tree of the multiplier by using this method to achieve the purpose of optimization. However, the traditional multiplication and addition fusion is to add the addend as a partial product to the Wallace tree of the multiplier, which leads to an irregular struc...

AI Technical Summary

Problems solved by technology

Although the traditional fused multiply-adder designed in this way is very fast, the delay on the critical path increases logarithmically with the increase in the number of bits of the traditional fused multiply-adder

Wallace tree will also cause other problems, such as wasting layout area, increasing complexity, etc.

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