在嵌入式系統(tǒng)常需用到多個串口，但常用的ARM微控制器上只有3個串口，常常不能滿足需要。針對TQ2440開發(fā)板的特點，介紹了在TQ2440開發(fā)板中利用TL16C554A芯片來擴展串口的方案， 并給出了硬件原理圖和部分程序。詳細闡述了S3C2440芯片與TL16C554芯片之間的接口設計和擴展串口驅動程序的移植。最后對串口進行了測試，使Linux系統(tǒng)的啟動信息通過擴展串口顯示出來。

　　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.