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设计了一款基于PCI总线的485通讯卡固件程序。其主要功能是对上位机的数据处理并下传给下位机;对下位机进行扫描,看有否数据上传,并将上传的数据传输给上位机。程序主要分五个模块:主程序模块、初始化模块、下发数据模块、上传数据模块和呼叫上传模块。该通信卡实现了上传下达的功能,避免了传输过程中的同步传输问题。
Design a PCI bus-based 485 communication card firmware program. Its main function is to process the data of the host computer and download it to the lower computer. Scan the lower computer and see if there is any data to be uploaded, and upload the uploaded data to the host computer. The program is mainly divided into five modules: the main program module, initialization module, send data module, upload data module and call upload module. The communication card realizes the function of uploading and transmitting, and avoids the problem of synchronous transmission in the transmission process.