基于CPLD的多串口扩展系统设计与测试

Design and Test of the Multiple Serial Ports Extension System Based on CPLD

系统基于ALTERA的CPLD EPM7064,针对嵌入式系统的精简特性,设计利用1个中断源高效管理多个串口。将普通PC主机上的一个USB接口扩展为8个通用串行接口,并在设备驱动程序中将这8个串口作为虚拟串口,使得主机可以如同操作本机串口一样通过USB口对串口设备进行数据读取。从而满足了单台PC主机同时连接多台串口设备的需求,而且保证了多个串口中断的无漏监测与服务。

The system based on the ALTERA CPLD of EPM7064, aims at the simplification speciality of the embedded system, uses single interrupt source to manage multiple serial ports. It can expand one USB port on PC into eight general serial ports, and in the device driver the 8 serial ports were used as virtual serial ports, then the host can use these serial ports through the USB port as the common ones locally. This meets the need of the single PC host to connect with many serial devices at the same time, also guarantees the inspection and service to several interruptions from serial ports without any leak.