摘要
为了保护NiosⅡ嵌入式系统的运行现场,在掉电之前,需要把系统的重要数据保存在非易失存贮器中。针对这种保存的数据量不大特点,本文提出采用"NiosⅡ+AT24C02"设计方案,在介绍AT24C02A芯片主要特性和分析I2C通信协议原理基础上,重点介绍NiosⅡ与AT24C02A之间接口电路的设计方法,包括接口电路的寄存器定义、逻辑功能模块设计和驱动程序的编写三个方面的内容,利用嵌入式逻辑分析仪(SigalTapⅡLogic Analyzer)来分析接口信号时序,分析结果表,本接口所产生的读写时序满足I2C的通信协议要求,验证了设计的正确性。
Some important data of system is saved to Non-volatile memory before power-down for protecting operating environment based Nios Ⅱ embedded systems from damage. For the feature of small amount of data saved, a ＂Nios Ⅱ ＋ AT24C02＂design scheme is proposed in this paper. After the main AT24C02A featurers and I2C bus communication protocol being introduced, the design method of interface circuit between Nios Ⅱ and AT24C02A is introduced, including the definition of interface registers, the design of logic function module and driver writing. SigalTap Ⅱ Logic Analyzer is adopted to analyze the timing of interface signals. Analying results show that the timing created by interface meet the requirements of I2C bus communication protocol, verifying the correctness of the design.
出处
《国外电子测量技术》
2009年第10期44-46,共3页
Foreign Electronic Measurement Technology
基金
广西壮族自治区教育厅科研项目(200808LX382)
南宁师范高等专科学校科研项目经费资助(ZRYJRCYB-02)
