单片机查表程序设计

$INCLUDE(C8051F020.INC)
BIT_COUNT DATA 07FH
TIMER DATA 07EH
TIMER1 DATA 07DH
TEN DATA 07CH
DA TA_IN DATA 020H
DA TA_OUT DATA 021H
DA TA_OUT1 DA TA 022H
DA TA_OUT2 DA TA 023H
DA TA_OUT3 DA TA 024H
DA TA_OUT4 DA TA 025H
CLK BIT P1.6
DAT BIT P1.7
ORG 0000H
JMP START
ORG 0100H
START: mov WDTCN, #0deh ; disable watchdog timer mov WDTCN, #0adh
mov OSCXCN, #67h ; enable external crystal
; oscillator at 22.1184MHz
clr A ; wait at least 1ms
djnz acc, $ ; wait ~512us
djnz acc, $ ; wait ~512us
osc_wait: ; poll for XTLVLD-->1
mov a, OSCXCN
jnb acc.7, osc_wait
orl OSCICN, #08h ; select external oscillator as
; system clock source
orl OSCXCN, #80h ; enable missing clock detector
CP1INIT: mov CPT1CN, #080h ; Comparator 1 Control Register
mov A, #010h ;CPT1CN
djnz ACC, $ ;CPT1CN wait at least 20us
anl CPT1CN, #not(30h)
mov EIP1, #040h
MOV TIMER,#50
PORTINIT:mov XBR2, #044h
mov P0MDOUT, #001h
DELAY0: MOV TIMER1,#255
DELAY1: DJNZ TIMER1,DELAY1
DJNZ TIMER,DELAY0
ANL P5,#00H
MOV DA TA_OUT,#10100100B
CALL SEND
ORL P5,#80H
MAIN://MOV R0,0X00
//SUBB CPT1CN,R0
//JNZ MAIN
MOV A,CPT1CN ;等待有键按下,发送读键盘指令
ANL A,#40H
JNZ MAIN
MOV DA TA_OUT,#00010101B ;
CALL SEND
CALL RECEIVE
ANL P5,#80H
CALL SEARCH
MOV A,R2
ANL A,#0FH
MOV DATA_OUT2,A
MOV A,R2
SW AP A
ANL A,#0FH
MOV DATA_OUT1,A
MOV A,R3
ANL A,#0FH
MOV DATA_OUT4,A
MOV A,R3
SW AP A
ANL A,#0FH
MOV DATA_OUT3,A
MOV DATA_OUT,#10100100B
CALL SEND
MOV DATA_OUT,#11001011B
CALL SEND
MOV DATA_OUT,DATA_OUT1
CALL SEND
MOV DATA_OUT,#11001010B
CALL SEND
MOV DATA_OUT,DATA_OUT2
CALL SEND
MOV DATA_OUT,#11001001B
CALL SEND
MOV DATA_OUT,DATA_OUT3
MOV DATA_OUT,#11001000B
CALL SEND
MOV DATA_OUT,DATA_OUT4
CALL SEND
//MOV B,#10
//MOV A,DATA_IN
//DIV AB
//MOV TEN,A
//MOV DATA_OUT,#10100001B
//CALL SEND
//MOV DATA_OUT,#10100001B
//CALL SEND
//MOV DATA_OUT,#10000001B
//CALL SEND
//MOV DATA_OUT,TEN
//CALL SEND
//MOV DATA_OUT,#10000000B
//CALL SEND
//MOV DATA_OUT,B
//CALL SEND
ANL P5,#80H
WAIT: MOV A,CPT1CN ;等待按键放开
ANL A,#40H
ORL A,#00H
JZ W AIT
JMP MAIN
SEND: MOV BIT_COUNT,#8 ;发送字符子程序ANL P5,#00H
CALL LONG_DELAY
SEND_LOOP:MOV C,DA TA_OUT.7
MOV DA T,C
SETB CLK
MOV A,DA TA_OUT
RL A
MOV DA TA_OUT,A
CALL SHORT_DELAY
CLR CLK
CALL SHORT_DELAY
DJNZ BIT_COUNT,SEND_LOOP
CLR DAT
RET
RECEIVE:MOV BIT_COUNT,#8 ;接收字符子程序
CALL LONG_DELAY
RECEIVE_LOOP:SETB CLK
CALL LONG_DELAY
MOV A,DATA_IN
RL A
MOV DA TA_IN,A
MOV C,DAT
MOV DA TA_IN.0,C
CLR CLK
CALL SHORT_DELAY
DJNZ BIT_COUNT,RECEIVE_LOOP
CLR DA T
RET
LONG_DELAY: MOV TIMER,#150 ;延时约200US DELAY_LOOP: DJNZ TIMER,DELAY_LOOP
RET
SHORT_DELAY: MOV TIMER,#20 ;延时约20US SHORT_LP: DJNZ TIMER,SHORT_LP
RET
SEARCH: MOV DPTR,#TABLE
MOV A,DATA_IN
RL A
MOV B,A
MOVC A,@A+DPTR
MOV R2,A
CLR A
MOV A,B
INC A
MOVC A,@A+DPTR
MOV R3,A
RET
TABLE:DW 8000H,8001H,8002H,8003H
DW 8004H,8005H,8006H,8007H
END。