嵌入式微处理器浮点执行部件EMFPU的设计

DESIGN OF EMFPU IN EMBEDDED MICROPROCESSOR

浮点执行部件是微处理器的重要组成部分。重点论述了基于 MIL-STD-1 75 0 A标准的嵌入式微处理器浮点执行部件 EMFPU (Embedded Floating Point Unit)采用的独特数据通路和控制机制。设计给出的 FPU是由指数部件和尾数部件两套数据通路组成 ,通过一套特殊的控制机制控制其协作完成各项功能。着重讨论了 FPU的算法、数据通路、控制通路和时序 ;

An embedded microprocessor generally needs to process fixed point and floating point data. Traditionally, two executive units will be separately designed for each kind of data processing. Which increases the scale and complexity of the whole processor. In this paper, a new method is presented to design a floating point unit of an embeded processor (EMFPU), which could process fixed point data as well as floating point one. The whole design is based on MIL-STD-1750A. The architecture and implementation of the EMFPU have been shown in detail, and the resolution of the relative bottleneck problem has been discussed elaborately. Firstly, according to the special data format, the algorithms are chosen to be reasonable, and then the datapath and the control logic are designed, while it must be sure to make the two parts work harmoniously. At last, the bottleneck of the whole circuit has been located and removed. The EMFPU is described in VHDL, and verified by ALTERA FPGA. The simulation and verification result shows the design successful.