keybd.asm

信号AD转换程序 信号AD转换程序 内容不多

keybd:mov r1,#0fdh
      mov a,#00h
      movx @r1,a
      mov r1,#0fbh
      movx a,@r1
      anl a,#38h
      jz keybd
      mov r5,#0eh
d15ms:acall d1ms
      djnz r5,d15ms
      mov r2,#0feh
      mov r0,#0fdh
      mov r1,#0fbh
keyb2:mov a,r2
      movx @r0,a
      movx a,@r1
      anl a,#38h
      mov r3,a
      cjne a,#38h,keyb3
      mov a,r2
      rl a
      mov r2,a
      xrl a,#0f7h
      jnz keyb2
      ajmp keybd
keyb3:mov a,r2
      anl a,#07h
      orl a,r3
      mov 06h,a
      mov r4,#00h
      mov dptr,#keytbl
keyb4:mov a,r4
      movc a,@a+dptr
      cjne a,06h,neq
      ajmp eqq
neq:  inc r4
      ajmp keyb4
eqq:  mov r5,#0eh
dly:  acall d1ms
      djnz r5,dly
      mov a,#00h
      movx @r0,a
      movx a,@r1
      anl a,#38h
      cjne a,#38h,eqq

ads:  mov a,r4
      mov dpl,a
      mov dph,#7fh
      setb it1
      setb ea
      setb ex1
      acall pin1

das:  mov dptr,#0b000h
      movx @dptr,a
      ret
      
      
pin1: mov a,r4
      mov dpl,a
      mov dph,#7fh
      movx a,@dptr
      mov 30h,a
      movx @dptr,a
      sjmp $
      reti


d1ms: mov r7,#64h
dlay: nop
      nop
      nop
      djnz r7,dlay
      reti

keytbl:db 00110110
       db 00101110
       db 00011110
       db 00110101
       db 00101101
       db 00011101
       db 00110011
       db 00101011
       db 00011011