電話IC卡讀錢程序

RST EQU P1.6 ;C2
CLK EQU P1.5 ;C3
DIO EQU P1.1 ;C7
LCALL READM
MOV 30H,R2
MOV 31H,R3
LJMP $
;=================
READM:
CLR RST
CLR CLK
LCALL DELAY
SETB RST
LCALL DELAY
LCALL CLOCK
CLR RST
LCALL DELAY
SETB DIO
MOV A,#64
LCALL CLOCK
DJNZ ACC,$-3
MOV R2,#0
MOV R3,#0
MOV R4,#40H
MOV R5,#96H
LCALL ADDM
MOV R4,#05H
MOV R5,#12H
LCALL ADDM
MOV R4,#00H
MOV R5,#64H
LCALL ADDM
MOV R5,#08H
LCALL ADDM
MOV R5,#01H
ADDM: MOV R6,#8
MOV C,DIO
JNC NEXT
MOV A,R3
ADD A,R5
DA A
MOV R3,A
MOV A,R2
ADDC A,R4
DA A
MOV R2,A
NEXT: LCALL CLOCK
DJNZ R6,ADDM+2
RET
CLOCK:
SETB CLK
LCALL DELAY
CLR CLK
DELAY: MOV R7,#4
DJNZ R7,$
RET