说明：此程序使用标准PS2键盘输入，LCD1602液晶屏输出显示。此样例仅作测试使用

晶振使用12M或者11.0592M,本键盘使用部分字母和数字测试，其他按键不能使用，用

户可以自行扩展。由于开发板和程序的各种参数，程序中没有使用奇偶校验，不保证没有

误码,校验程序请自行添加。-Descr iption: This program uses the standard PS2 keyboard input, LCD1602 LCD output display. This sample is only used for testing the use of crystal 12M or 11.0592M, this keyboard to use part of letters and numbers tests, other buttons can not be used, users can expand their own. As the development board and procedures for various parameters, the program does not use parity, does not guarantee that there is no error, verification procedures to add your own.