冯春阳,张遂南

摘 要:为解决没有三线制同步串口的微处理器与外围串行设备通信困难的问题,通过研究三线制同步串行通信的机理,首先构建基于传统设计所实现的硬件电路接口,然后利用可编程逻辑器件PLD,设计基于CPLD/FPGA的三线制同步串行通信控制器通用接口。通过对各功能模块的详细介绍,实现硬件电路的小型化和灵活移植性,减小了整个系统的体积和功耗。经实际项目使用,结果表明基于该接口结构实现了微处理器与外围串行设备间的三线制同步串行通信的功能。

关键词:三线制;同步串行通信;接口;PLD;CPLD/FPGA

中图分类号:TP336文献标识码:A

文章编号:1004-373X(2009)19-080-03

Design of Three-wire Synchronous Serial Communication Interface

FENG Chunyang,ZHANG Suinan

(Xi′an Microelectronic Technology Institute,Xi′an,710054,China)

Abstract:In order to resolve difficulty of the communication between processor without three-wire synchronous serial interface and peripheral serial equipment,after studying the principle of three-wire synchronous serial communication,hardware circuit based on traditional method is introduced.Adopting PLD technology,universal interface of three-wire synchronous serial communication based on CPLD/FPGA,particularly each functional module are introduced,the miniaturization and flexible transplant of hardware function are realized,and the volume and power of the system are reduced.In practical projects,the architecture based on CPLD/FPGA has realized function of the synchronous serial communication between the processor and peripheral equipment.

Keywords:three-wire principle;synchronous serial communication;interface;PLD;CPLD/FPGA

0 引 言

航天工程领域中,星地通讯等远距离遥测遥控是嵌入式卫星数管计算机重要功能之一,利用三线制同步串行[1]遥测遥控通道对指令和数据进行收发操作是通信链路的重要环节。

目前许多处理器芯片都已集成了同步串行接口,但基于三线制同步串行[2]接口的处理器并不多。利用传统设计方法[3]所实现的三线制同步通信硬件电路接口虽然能满足一般工程设计要求,但在“低成本、小体积、低功耗和灵活性”设计理念的推动下,传统设计显然弊大于利。采用可编程逻辑器件CPLD/FPGA技术[4],对三线制同步串行通信接口电路进行结构设计与实现,可以大幅度减小系统体积,降低功耗,提高设计的灵活度。同时,还可以在其中增加其他逻辑功能模块,并能很方便地应用到相关的嵌入式系统中。……