51单片机课程设计讲稿.ppt

* * 一、键盘 矩阵式键盘 判别是否有键按下： JugeKeyPressed: CLR A MOV P1,#0FFH ANL P1, ;列线低电平，判断行线是否有低电平 MOV A,P1 ORL A, CPL A ;A=0说明无键按下，A≠0说明有键按下 RET 消抖判键： JugekeyBoard: LCALL JugeKeyPressed JZ JugeKeyEnd ;如果A不为0，有键按下 LCALL Delay10ms ;去抖动 LCALL JugeKeyPressed ;再次判断有无键按下 JZ JugeKeyEnd SETB KeyPressed ;设置键盘按下标志 JugeKeyEnd: RET 识别键值： JugeWhichKey： MOV ScanTimes,#04H MOV A, ;P1.4置低不影响其他列 ScanLoop： ORL P1, ANL P1,A ;判断P1.4对应列是否有键按下 MOV WhichCol，A MOV A,P1 MOV InputedKey,A ;存储输入键值 ORL A , CPL A ;若P1.4对应列有键按下，则a≠0 JZ ScanNextRow ; P1.4列没有键按下，继续下一列 LJMP Keycode ScanNextRow： MOV A,WhichCol RL A MOV WhichCol,A ;逐列置低电平 DJNZ ScanTimes,ScanLoop CLR KeyPressed ;四列循环完毕后认为没有键按下 LJMP JugeKeyOver E7 S16 ED S8 D7 S15 DD S7 B7 S14 BD S6 77 S13 7D S5 EB S12 EE S4 DB S11 DE S3 BB S10 BE S2 7B S9 7E S1 键值 按键 键值 按键 Keycode:MOV A,InputedKey CJNE A,#7EH,Not01 MOV InputedKey,#01H LJMP JugeKeyOver Not01: CJNE A,#0BEH,Not02 MOV InputedKey,#02H LJMP JugeKeyOver Not02: CJNE A,#0DEH,Not03 MOV InputedKey,#03H LJMP JugeKeyOver Not03: CJNE A,#0EEH,NotOrder SETB OrderKeyPressed LJMP JugeKeyOver NotOrder: CJNE A,#7DH,Not04 MOV InputedKey,#04H LJMP JugeKeyOver Not04: CJNE A,#0BDH,Not05 MOV InputedKey,#05H LJMP JugeKeyOver Not05: CJNE A,#0DDH,Not06 MOV InputedKey,#06H LJMP JugeKeyOver Not06: CJNE A,#0EDH,NotFun SETB FunKeyPressed LJMP JugeKeyOver NotFun: CJNE A,#7BH,Not07 MOV InputedKey,#07H LJMP JugeKeyOver Not07: CJNE A,#0BBH,Not08 MOV InputedKey,#08H LJMP JugeKeyOver Not08: CJNE A,#0DBH,Not09 MOV InputedKey,#09H LJMP JugeKeyOver Not09: CJNE A,#0EBH,NotEnter SETB EnterKeyPressed JMP JugeKeyOver NotEnter:CJNE A,#77H,Not00 MOV InputedKey,#00H LJMP JugeKeyOver Not00: CJNE A,#0B7H,NotUp SETB UpKeypressed LJMP JugeKeyOver NotUp: CJNE A,#0D7H,NotDown SETB DownKeyPressed LJMP JugeKeyOver NotDown: CJNE A,#0E7H,InputFail SETB ExitKeyPres