key8155.asm

来自「信号AD转换程序 信号AD转换程序 内容不多」· 汇编 代码 · 共 53 行

keybd: acall ks1
       jnz key1 ;有键闭合
       ajmp keybd
       mov r5,#0eh
key0:  acall d1ms
       djnz r5,key1
       mov r2,#0feh
       mov r4,#00h
key1:  mov dptr,#7f01h
       mov a,r2
       movx @dptr,a
       inc dptr
       inc dptr
       movx a,@dptr
       jb acc.0,lone
       mov a,#00h
       ajmp lkp
lone:  jb acc.1,rnext
       mov a,#04h
lkp:   add a,r4
       push a
       mov r5,#0eh
key2:  acall d1ms
       djnz r5,key2
       acall ks1
       jnz key2
       pop a
       ret
rnext: inc r4
       mov a,r2
       jnb acc.4,knd
       rl a
       mov r2,a
       ajmp key1
knd:   ajmp keybd
ks1:   mov dptr,#7f01h
       mov a,#00h
       movx @dptr,a
       inc dptr
       inc dptr
       movx a,@dptr
       cpl a
       anl a,#0fh
       ret
d1ms:  mov r7,#64h
dlay:  nop
       nop
       nop
       djnz r7,dlay
       ret