基于UART的SPI扩展方法

借助于内置开关功能的RS－232接口LT1180A，巧妙利用UART方式0扩展SPI是一种较好的方法，首先阐述利用USAR扩展SPI的必要性和可行性，给出了硬件连接图，接着经过时序分析得出，进行适当的数据排序变换，可用UART方式0有效地模拟SPI操作，最后以串行F2PROM X25F128为例，着重介绍了扩展SPI的硬软件设计方法，实际应用表明，该方法经济，可靠，实用。

Method of Extending SPI Interface Based on UART

It is the better method to extend SPI interface by making full use of UART's mode 0 skillfully and LT1180A which is a RS 232 interface with on/off function. Firstly, this paper explains the necessary and possibility of extending SPI interface using UART and gives hardware connecting chart. Secondly, it is concluded through analyzing time order that simulating SPI operation using UART mode 0 is effective after proper data transformation. Lastly, using the serial E 2PROM X25F128 as an example, the paper mostly introduces the design method of hardware and software for extending the serial peripheral interface. Practical application shows that the method has remarkable characteristics in economy, reliability and practicality.