摘要
MPC860作为一款功能强大的嵌入式通信处理器,缺乏对USB的支持必然限制其在某些领域的应用;所以提出了一种基于FT245BM实现MPC860USB通信接口的方法;实现FT245BM和处理器的连接有两种通用的方法:使用处理器的I/O口或使用CPLD译码,鉴于MPC860I/O口为复用引脚,使用I/O口法很浪费资源,而使用CPLD译码又增加了系统的成本和复杂性,所以使用MPC860的存储控制器UPMA,通过微指令编程实现FT245BM要求的控制逻辑时序;给出了详细的软硬件设计,并且介绍了使用FTDI提供的VCP(Virtual COM Port)驱动编写PC机端的通信软件的方法;经过测试,通信稳定可靠,实现了在MPC860上扩展USB接口的目的。
Being an embedded communication processor which has formidable function, MPC860 not supporting USB will limits its application in some domain. So a method based on FT245BM to realize the MPC860＇s USB communicationg interface is been raised. There are two means to connect processor with FT245BM, one through the I/O ports of processor and the other though coding of CPLD. Because the I/O port of MPC860 are multiplexing , this method wastes the I/O port resource; Yet the CPLD coding will increase the cost and complexity of the product. S o The control logic sequences needed by FT245BM are realized through microinstruction programming in the MPC860 memory controller UPMA. The hardware and software design are describe in detail. And the method through VCP （Virtual COM Port） driver provided by FTDI to programme communication software on the PC is show as well. The testing prove the communication is stable and reliable , and the purpose to realize the USB interface on MPC860 is reached.
出处
《计算机测量与控制》
CSCD
2007年第12期1838-1840,1849,共4页
Computer Measurement &Control
