基于SD7218A的键盘和LED显示设计与实现

Design and Realization of Keyboard and LED Display Based on SD7218A

基于显示驱动芯片SD7218A设计一种键盘和LED的显示电路。在分析SD7218A芯片的串行接口通信规范与I2C总线的通信规范异同的基础上,提出一种用标准I2C接口开发该串行接口的一种方法。其间利用LPC2131的I2C接口与SD7218A的串行接口相连设计硬件电路,结合I2C总线与模拟该串行通信模式设计软件代码,给出了具体的程序流程图及关键程序。该设计仅使用两根信号线,硬件设计简单,在软件设计中结合使用了硬件I2C接口,简化了软件设计同时也提高了系统的稳定性。

Based on the display driver chip SD7218A, the LED display controller for the keyboard has been designed. The communication principle between the chip＇s serial interface and I^2C interface was analyzed. A method of developing the serial interface by using I^2C interface was introduced. The hardware circuit cool was designed by connecting the I^2C interface integrated in LPC2131 and the serial interface of SD7218A. The system software code was designed by combining the I^2C bus and software simulation of the chip＇s serial communication mode. Besides, the program control flow was given as well as key programs. For hardware design, this method only uses two signal wires which simplified the circuit. For software design, it makes use of hardware I^2C interface which simplified the design and enhanced the stability of the system.