TMS2407开发平台键盘LED试验，键盘输入0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f，LED输出0,1,2,3,4,5,6,7,8,9,-,E,H,L,NU-press the key and the leds display the key value! the key value is from:0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f the leds dislay the value as:0,1,2,3,4,5,6,7,8,9,-,