ds1302-ini.txt

时间芯片ds1302初始化程序

sclk   bit  90H          ;p1.0=sclk
io     bit  91H           ;P1.1=I/O
RST    BIT  92H           ;P1.2=RST
;PSW.5  BIT  0D5H           ;READ:PSW.5=1;WRIT:PSW.5=0
SEC    DATA 60H            ;SECOND
MIN    DATA  61H            ;MINUTE
HR     DATA  62H             ;HR
DATE   DATA  63H           ;SATE
MONTH  DATA  64H            ;MONTH
DAY    DATA  65H            ;DAY
YEAR   DATA  66H
         ORG   0000H
         MOV  SP,#30H
LCALL  INIT
START:   MOV  R0,#SEC
MOV  R7,#7
SETB  PSW.5
LCALL RWRTC
LJMP  START
; *********************
RWRTC:   MOV  B,#10000001B   ;READ DS1302
JB  PSW.5,RWRTC1
MOV  B,#10000000B    ;WRITE DS1302
RWRTC1:  CLR  SCLK            ;SCLK=VIL
NOP
SETB  RST          ;RST=VIH
MOV  R6,#8
MOV  A,B
RWRTC2:  CLR  SCLK          ;SCLK=VIL
RRC  A
MOV  IO,C           ;WRITE COMMAND
NOP
SETB  SCLK           ;SCLK=VIH
DJNZ  R6, RWRTC2
MOV  R6,#8
JNB  PSW.5, RWRTC4
RWRTC3: 
CLR  SCLK              ;SCLK-VIL
NOP
MOV  C,IO                 ;READ DATA
RRC  A
SETB  SCLK              ;SCLK=VIH
DJNZ  R6, RWRTC3
MOV  @R0,A
SJMP  RWRTC6
RWRTC4:   MOV  A,@R0
RWRTC5:   CLR  SCLK                 ;SCLK=VIL
RRC  A
MOV  IO,C                   ;WRITE SATA
NOP
SETB  SCLK                ;SCLK=VIH
DJNZ  R6,RWRTC5
RWRTC6:   INC  R0                    ;NEXT SDDRESS/DATA
MOV  A,B
ADD  A,#00000010B         ;SDDRESS+1
MOV  B,A
CLR  RST                   ;RST=VIL
NOP
CLR  SCLK                  ;SCLK=VIL
DJNZ  R7,RWRTC1
RET
;***************************************************************
WRRTC:    CLR  SCLK
NOP 
SETB  RST
NOP
NOP
MOV  R7,#2
WRRTC1:    MOV  R6,#8
MOV  A,@R0
CLR  C
WRRTC2:    CLR  SCLK
RRC  A
MOV  IO,C
NOP
SETB  SCLK
DJNZ  R6, WRRTC2
INC  R0
DJNZ  R7, WRRTC1
CLR  RST
NOP
CLR  SCLK
RET
;*********************************************************************







INIT:      CLR  SCLK
CLR  RST
MOV  SEC,#10001110B           ;OPEN WRITE PROTECTION
MOV  MIN,#00000000B           ;
MOV  R0,#SEC
LCALL WRRTC
MOV  SEC,#10010000B                ;R1=2K,1 DIODE
MOV  MIN,#10100101B              
MOV  R0,#SEC
LCALL  WRRTC
MOV  SEC,#10000000B              ;START TIMER
MOV  MIN,#00000000B
MOV  R0,#SEC
LCALL WRRTC
RET
END