;DS18B20汇编程  试验板显示温度值 2007-1-27 17:00:34 
ORG 0000H
AJMP STAR
STAR:
TEMPER_L EQU 36H
TEMPER_H EQU 35H
TEMPER_NUM EQU 60H
FLAG1 BIT 00H
DQ BIT P2.5 
AAA:MOV SP,#70H
LCALL GET_TEMPER
LCALL TEMPER_COV
;mov  temper_num,#56
LCALL DISPLAY;调用显示子程序

LJMP AAA
NOP
;------------------读出转换后的温度值
GET_TEMPER:
SETB DQ ; 定时入口
BCD:LCALL INIT_1820
JB FLAG1,S22

S22:LCALL DELAY1
MOV A,#0CCH ; 跳过ROM匹配------0CC
LCALL WRITE_1820
MOV A,#44H ; 发出温度转换命令
LCALL WRITE_1820
NOP
LCALL DELAY
LCALL DELAY
CBA:LCALL INIT_1820
JB FLAG1,ABC
LJMP CBA
ABC:LCALL DELAY1
MOV A,#0CCH ; 跳过ROM匹配
LCALL WRITE_1820
MOV A,#0BEH ; 发出读温度命令
LCALL WRITE_1820
LCALL READ_18200 ;READ_1820
RET
;------------------读DS18B20的程序,从DS18B20中读出一个字节的数据
READ_1820:
MOV R2,#8
RE1:
CLR C
SETB DQ
NOP
NOP
CLR DQ
NOP
NOP
NOP
SETB DQ
MOV R3,#7
DJNZ R3,$
MOV C,DQ
MOV R3,#23
DJNZ R3,$
RRC A
DJNZ R2,RE1
RET

;-------------------写DS18B20的程序
WRITE_1820:
MOV R2,#8
CLR C
WR1:
CLR DQ
MOV R3,#6
DJNZ R3,$
RRC A
MOV DQ,C
MOV R3,#23
DJNZ R3,$
SETB DQ
NOP
DJNZ R2,WR1
SETB DQ
RET
;-------------------读DS18B20的程序,从DS18B20中读出两个字节的温度数据
READ_18200:
MOV R4,#2 ; 将温度高位和低位从DS18B20中读出
MOV R1,#36H ; 低位存入36H(TEMPER_L),高位存入35H(TEMPER_H)
RE00:
MOV R2,#8
RE01:
CLR C
SETB DQ
NOP
NOP
CLR DQ
NOP
NOP
NOP
SETB DQ
MOV R3,#7
DJNZ R3,$
MOV C,DQ
MOV R3,#23
DJNZ R3,$
RRC A
DJNZ R2,RE01
MOV @R1,A
DEC R1
DJNZ R4,RE00
RET

;-------------------将从DS18B20中读出的温度数据进行转换
TEMPER_COV:
MOV A,#0F0H
ANL A,TEMPER_L ; 舍去温度低位中小数点后的四位温度数值
SWAP A
MOV TEMPER_NUM,A
MOV A,TEMPER_L
JNB ACC.3,TEMPER_COV1 ; 四舍五入去温度值
INC TEMPER_NUM

TEMPER_COV1:
MOV A,TEMPER_H
ANL A,#07H
SWAP A
ORL A,TEMPER_NUM
MOV TEMPER_NUM,A ; 保存变换后的温度数据
;LCALL BIN_BCD
RET
;-------------------将16进制的温度数据转换成压缩BCD码
BIN_BCD:
MOV DPTR,#TEMP_TAB
MOV A,TEMPER_NUM
MOVC A,@A+DPTR
MOV TEMPER_NUM,A
RET

TEMP_TAB:
DB 00H,01H,02H,03H,04H,05H,06H,07H
DB 08H,09H,10H,11H,12H,13H,14H,15H
DB 16H,17H,18H,19H,20H,21H,22H,23H
DB 24H,25H,26H,27H,28H,29H,30H,31H
DB 32H,33H,34H,35H,36H,37H,38H,39H
DB 40H,41H,42H,43H,44H,45H,46H,47H
DB 48H,49H,50H,51H,52H,53H,54H,55H
DB 56H,57H,58H,59H,60H,61H,62H,63H
DB 64H,65H,66H,67H,68H,69H,70H,71H
DB 72H,73H,74H,75H,76H,77H,78H,79H
DB 80H,81H,82H,83H,84H,85H,86H,87H
DB 88H,89H,90H,91H,92H,93H,94H,95H
DB 96H,97H,98H,99H

;-------------------DS18B20初始化程序
INIT_1820:
SETB DQ
NOP
CLR DQ
MOV R0,#80H
TSR1:
DJNZ R0,TSR1 ; 延时
SETB DQ
MOV R0,#25H ;96US-25H
TSR2:
DJNZ R0,TSR2
JNB DQ,TSR3
LJMP TSR4 ; 延时
TSR3:
SETB FLAG1 ; 置标志位,表示DS1820存在
LJMP TSR5
TSR4:
CLR FLAG1 ; 清标志位,表示DS1820不存在
LJMP TSR7
TSR5:
MOV R0,#06BH ;200US
TSR6:
DJNZ R0,TSR6 ; 延时
TSR7:
SETB DQ
RET
;------------------重新写DS18B20暂存存储器设定值
RE_CONFIG:
JB FLAG1,RE_CONFIG1 ; 若DS18B20存在,转RE_CONFIG1
RET
RE_CONFIG1:
MOV A,#0CCH ; 发SKIP ROM命令
LCALL WRITE_1820
MOV A,#4EH ; 发写暂存存储器命令
LCALL WRITE_1820

MOV A,#00H ; TH(报警上限)中写入00H
LCALL WRITE_1820
MOV A,#00H ; TL(报警下限)中写入00H
LCALL WRITE_1820
MOV A,#7FH ; 选择12位温度分辨率
LCALL WRITE_1820
RET
;------------------延时子程序
DELAY:MOV R7,#00H
MIN:DJNZ R7,YS500
RET
YS500:LCALL YS500US
LJMP MIN
YS500US:MOV R6,#00H
DJNZ R6,$
RET
DELAY1:MOV R7,#20H
DJNZ R7,$ 
RET

;显示子程序
display:
main1: ;主程序大循环
call clockup
call disp ;LED数码显示
call d10ms ;延时

djnz 57h,main1
mov 57h,#20
djnz 58h,main1
mov 58h,#90

clockup:
mov a,temper_num
mov b,#10
div ab ;将秒计算后送入显示缓存
mov 40h,b
mov 41h,a
ret

disp:
inc 48h
mov a,48h
mov p1,#0ffh
cjne a,#8,ds0
mov 48h,#0
mov a,48h

ds0:cjne a,#0,ds1
mov p3,#00010000b
mov a,40h
call ledtab
jmp edisp

ds1:cjne a,#1,edisp
mov p3,#00001000b
mov a,41h
call ledtab
jmp edisp

edisp:ret

ledtab:
	mov dptr,#table
	movc a,@a+dptr
	cpl a
	mov p1,a
	ret

d10ms:;延时程序,根据晶振来改参数
mov r5,#3
dddd:mov r4,#10
djnz r4,$
djnz r5,dddd
ret

table: DB 0FAH,22H,0B9H,0ABH,063H,0CBH,0DBH,0A2H,0FBH,0EBH,0F3H,5BH,0D8H,03BH,0D9H,0D1H,01h,00h


End