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基于SPI互連的多串口系統(tǒng)

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

資料介紹

?針對個(gè)人計(jì)算機(jī)只有1～2個(gè)串口，給同時(shí)連接多個(gè)串口設(shè)備進(jìn)行聯(lián)合測量帶來的不便，提出了一種由多個(gè)單片機(jī)基于高速同步串行接口（SPI）互連的串口擴(kuò)展方法。采用此方法所建的系統(tǒng)只需占用1個(gè)現(xiàn)有的串口或USB口，就可連接3個(gè)以上的串口設(shè)備。該系統(tǒng)由多個(gè)STC12C5410AD單片機(jī)構(gòu)成主體，該型號單片機(jī)同時(shí)具有UART和SPI。系統(tǒng)中的單片機(jī)以“單主—多從”結(jié)構(gòu)進(jìn)行SPI總線互連，主機(jī)與從機(jī)通過SPI方式交換信息和數(shù)據(jù)，每個(gè)從機(jī)的串口可以連接1個(gè)外部串口設(shè)備并交換數(shù)據(jù)，同時(shí)主機(jī)的串口可與上位計(jì)算機(jī)相連，從而實(shí)現(xiàn)上位計(jì)算機(jī)通過該系統(tǒng)與多個(gè)下位串口設(shè)備交換數(shù)據(jù)。系統(tǒng)中，主機(jī)和從機(jī)都開辟有一定的數(shù)據(jù)緩存區(qū)，并且使主機(jī)的數(shù)據(jù)吞吐率高于從機(jī)的總和。此外，還介紹了數(shù)據(jù)交換協(xié)議、存儲(chǔ)器的組織、軟件結(jié)構(gòu)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.