利用汇编语言实现4*4键盘的扫描，同时利用液晶屏显示出来，完美的消除了抖动，且每次按下只会显示一个值，不会因为按下过长而显示多个-Using assembly language to achieve 4* 4 keyboard scanning, while taking advantage of the LCD screen display, and perfectly eliminates the jitter。And each press will following display a value, will not press too long to display more than one！