一种嵌入式FPU的设计与实现

A Design of Special Purpose FPU

本文介绍了自主设计实现的浮点部件ＮＲＳＦＰＵ（Ｎｏｒｔｈｗｅｓｔｅｒｎ Ｐｏｌｙｔｅｃｈｎｉｃａｌ Ｕｎｉｖｅｒｓｉｔｙ ＲＩＳＣＳｙｓｔｅｍ′ｓＦｌｏａｔｉｎｇ Ｐｏｉｎｔ Ｕｎｉｔ）．为了优化设计规模和速度，在体系结构设计中采用了有效策略，并给出了ＮＲＳＦＰＵ 中复杂运算指令流程的设计．通过布局布线后的结果看出，该设计规模小，速度高。

To meet the needs of embedded application,this paper describes NRS FPU(Northwestern Polytechnical University RISC System′s Floating Point Unit)thoroughly.Our discussions in this paper centre on NRS FPU system architecture,basic arithmetic operation and transcendental function operation algorithms.NRS FPU is designed by a very popular way —— TOP DOWN and with RISC idea.Since add and shift are two basic operations in arithmetic circuits,many algorithms based on them are conceived to implement complex arithmetic functions in this paper.Finally,it is shown that NRS FPU is much suitable for embedded application due to its small area and high speed from its layout.