The Design And Realization Of Multifunction Extended Serial Ports Based On EDA Design Method

In many application situations which are centered as MCU or DSP,it is often needed that a single micro-controller controls several peripheral equipments, but commonly there is a serial port in the most of micro-controller. And so in these situations, the serial ports of the micro-controller are needed to be extended. In applications, ST16c554,SP2538 and so on are used, but these methods have some defaults, for example, that Baud rate can't be changed ,and the speed of communication is a little slow.Based on these defaults, the article puts forward a new design method, which can extend a serial port to 5 serial ports. In this design, the working mode of ASIC can be controlled by its pins as single and multi channels mode. It means, the system can not only work when the baud rate of slave ports and mast port is same, but can work perfectly when baud rate is not same. At the same time, the design discards the traditional the principal and subordinate structure, and can response voluntarily to the requests of the peripheral equipments. So in upper level it is realized that the requests of peripheral equipments can be responded in time by the unit of main control; in addition, the design improve the serial port's structure of the MCS-51, and the changes can make the structure more simple.The article analyses the process of serial ports extended used by synchronous method, the design of all the modules, simulation in function, synthesis, and simulation after simulation and so on in order to guarantee reliability of the system.At the same time ,in the end of the article some methods are brought forward to improve the system.