基于S3C2440和嵌入式Linux的扩展串口设计

　　在嵌入式系统常需用到多个串口，但常用的ARM微控制器上只有3个串口，常常不能满足需要。针对TQ2440开发板的特点，介绍了在TQ2440开发板中利用TL16C554A芯片来扩展串口的方案， 并给出了硬件原理图和部分程序。详细阐述了S3C2440芯片与TL16C554芯片之间的接口设计和扩展串口驱动程序的移植。最后对串口进行了测试，使Linux系统的启动信息通过扩展串口显示出来。

　　Abstract:

　　Multi-serial ports are often widely used in embedded system. However， one ARM MCU has only three UART， which is unable to fulfill the requirement. Based on the characteristics of TQ2440 development board，this article introduces a way of expanding the serial ports of a personal computer using TL16C554A chip in the TQ2440 development board，and provides schematic diagram of hardware and part of program. The design of the interface between chips of S3C2440 and TL16C554A is given. The realization of drivers of the expansion ports are also explained. At last，this paper has given a test of multi-serial ports which displays thestarting information of Linux system.