面向SPICE仿真的专用浮点计算单元研究OACSTPCD

Sparse matrix solving is an important part of SPICE simulation.The operators currently used for solving are usually general-purpose floating-point calculation units.In order to solve the problem of double-precision floating-point speed in SPICE simulation,this article improves the addition/subtraction and multiplication units in general floating-point operators to enable faster solution speed in the context of SPICE simulation.The rounding parallel delay optimization algorithm and dual-path design scheme are used for the traditional addition and subtraction unit,and the critical path delay of the circuit is optimized by means of Shannon expansion and inexact leading zero compensation.For the traditional multiplication unit,the related delay is improved by changing the traditional compression topology layer structure and optimizing logic such as rounding and carry in the injection value algorithm.In the end,the double-precision floating-point solution achieved delays of 0.46 ns and 0.79 ns respectively under the TSMC 28 nm process.Compared with Synopsys'DW library unit,the delays are reduced by 33.4％and 7.1％respectively,and the area is reduced by 4.62％and 1.6％respectively.The experiment results show that the improved floating-point unit can effectively reduce the time of a single matrix solution step and accelerate the overall speed of transient simulation to a certain extent.