基于SPI互連的多串口系統

2512869 2010-12-10 | rar | 888 | 次下載 | 5積分

資料介紹

?針對個人計算機只有1～2個串口，給同時連接多個串口設備進行聯合測量帶來的不便，提出了一種由多個單片機基于高速同步串行接口（SPI）互連的串口擴展方法。采用此方法所建的系統只需占用1個現有的串口或USB口，就可連接3個以上的串口設備。該系統由多個STC12C5410AD單片機構成主體，該型號單片機同時具有UART和SPI。系統中的單片機以“單主—多從”結構進行SPI總線互連，主機與從機通過SPI方式交換信息和數據，每個從機的串口可以連接1個外部串口設備并交換數據，同時主機的串口可與上位計算機相連，從而實現上位計算機通過該系統與多個下位串口設備交換數據。系統中，主機和從機都開辟有一定的數據緩存區，并且使主機的數據吞吐率高于從機的總和。此外，還介紹了數據交換協議、存儲器的組織、軟件結構等。

Abstract:: ?Personal computer only has 1 or 2 serial ports， which causes inconvenience when multiple serial devices are required to communicate with the computer at the same time. Aiming at this problem， a new method of serial port expansion based on SPI had been proposed. The multi-serial-port system which used the new method only took a serial or USB port available， and can connect three or more serial devices. The main body of this system consisted of multiple single chip processors STC12C5410AD which had both UART and SPI. Those processors in this system communicated in“single master- more slaves” mode， and the master exchanged the information and data with the slave by SPI. Every slave chip can connect to a serial device， and the master chip connected with the host computer’s serial port. Thus， the data can be transferred from computer to serial devices or reverse through this multi-serial-port system. The master and the slave have some data buffers， and the data throughput of master is larger than that of all of the slaves. In addition， and the protocol of data exchange， memory organization， and the software structure are also described in this article.