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纯软件单片机串口(二)
这是另外一个使用中断查寻的程序!
www.ubicom.com or www.scenix.com
到UBICOM看看，那里的串口都是纯软件的
SEND_READ EQU 01H ;Bit for write(0) or read(1)
SEND_ENDS EQU 02H ;Bit for communiciating(1) or ends(0)
READ_ENDS EQU 03H ;Bit for reading(1) or ends(0)
READ_INT EQU 04H ;Bit intettupt sending to reading
BUAD_RAM_H EQU 30H ;Communite buad TH
BUAD_RAM_L EQU 31H ;Communite buad TL
SEND_TIME EQU 32H ;Send int times count
READ_TIME EQU 33H ;Read int times count
SEND_CODE EQU 34H ;Byte that may be send
READ_CODE EQU 35H ;Read ends value byte
READ_BUFF EQU 36H ;Read bit RRC
SEND_COUNT EQU 37H ;Send bit count
READ_COUNT EQU 38H ;Read bit count
SEND_FLAG EQU 39H ;Send byte flag (0-->start send)
READ_FLAG EQU 3AH ;Read byte flag (0-->check start bit)
TXD_LINE EQU P3.1;P1.6 ;TXD line
RXD_LINE EQU P3.0;P3.2 ;RXD line
BUAD_H EQU 0FFH ;9600 4800 2400 1200 600 300
BUAD_L EQU 0C3H ;FFE0 FFC0 FF80 FF00 FE00 FC00
ORG 0000H
SJMP MAIN
ORG 000BH
LJMP COMM_INT
ORG 0040H
MAIN: MOV IE,#00H
MOV SP,#62H
MOV P1,#0FFH
MOV P3,#0FFH
MOV R1,#30H ;Clr CPU RAM
MOV R2,#30H
LOOP: MOV @R1,#00H
INC R1
DJNZ R2,LOOP
MOV BUAD_RAM_H,#BUAD_H
MOV BUAD_RAM_L,#BUAD_L
MOV TMOD,#01H
MOV TH0,BUAD_RAM_H
MOV TL0,BUAD_RAM_L
SETB TR0
SETB ET0
SETB PT0
SETB EA
SETB SEND_ENDS
SETB READ_ENDS
LCALL SEND_TEST_CODE
LCALL TEST1
LOOP0: MOV R1,#40H
MOV R2,#00H
MOV READ_FLAG,#00H
SETB SEND_READ
LOOP1: ;SETB READ_ENDS
JB READ_ENDS,$
SETB READ_ENDS
MOV A,READ_CODE
MOV @R1,A
INC R1
INC R2
CJNE A,#3FH,NEXT1
SJMP NEXT2
NEXT1: CJNE R2,#20H,LOOP1
NEXT2: MOV R1,#40H
LOOP2: MOV SEND_FLAG,#00H
MOV SEND_CODE,@R1
CLR SEND_READ
JB SEND_ENDS,$
SETB SEND_ENDS
JB READ_INT,LOOP3
INC R1
DJNZ R2,LOOP2
SJMP LOOP0
LOOP3: CLR READ_INT
MOV R1,#40H
MOV R2,#00H
SJMP LOOP1
;LCALL SEND_TEST_CODE
MOV SEND_CODE,READ_CODE
CLR SEND_READ
MOV SEND_FLAG,#00H
SETB SEND_ENDS
JB SEND_ENDS,$
SJMP $
SJMP $
;**********************************************
TEST1: MOV READ_FLAG,#00H
SETB SEND_ENDS
MM1: MOV SEND_CODE,#3DH
MOV SEND_FLAG,#00H
MM3: ;CLR SEND_READ
JB SEND_ENDS,$
SETB SEND_ENDS
JNB READ_INT,MM1
CLR READ_INT
SETB READ_ENDS
JB READ_ENDS,$
MOV R7,#00H
DJNZ R7,$
MOV SEND_CODE,READ_CODE
MOV SEND_FLAG,#00H
SJMP MM3
RET
;******************************
SEND_TEST_CODE: MOV R6,#61H
MOV R7,#1AH
SEND_LOOP: MOV SEND_CODE,R6
CLR SEND_READ
MOV SEND_FLAG,#00H
SETB SEND_ENDS
INC R6
JB SEND_ENDS,$
DJNZ R7,SEND_LOOP
RET
;*********************************************************************
;* SEND_READ EQU 01H Bit for write(0) or read(1) *
;* SEND_ENDS EQU 02H Bit for communiciating(1) or ends(0) *
;* READ_ENDS EQU 03H Bit for reading(1) or ends(0) *
;* SEND_TIME EQU 30H Send int times count *
;* READ_TIME EQU 30H Read int times count *
;* READ_BUFF EQU 31H Read bit RRC *
;* SEND_COED EQU 32H Byte that may be send *
;* READ_CODE EQU 32H Read ends value byte *
;* SEND_COUNT EQU 33H Send bit count *
;* READ_COUNT EQU 33H Read bit count *
;* BUAD_RAM_H EQU 34H Communite buad TH *
;* BUAD_RAM_L EQU 35H Communite buad TL *
;* SEND_FLAG EQU 36H Send byte flag (0-->start send) *
;* READ_FLAG EQU 37H Read byte flag (0-->check start bit) *
;* TXD_LINE EQU P1.4 Data TXD line *
;* RXD_LINE EQU P1.3 Data RXD line *
;* When send: SETB SEND_ENDS // CLR SEND_READ *
;* MOV SEND_CODE,(Byte that will be send) *
;* MOV SEND_FLAG,#00H *
;* if COMM_ENDS is 0 that completed send communiciation. *
;* if COMM_FLAG isn't 03H the send communiciating has been *
;* interrupted by read communiciation. *
;* When read: SETB READ_ENDS // SETB SEND_READ *
;* MOV READ_FLAG,#00H *
;* if READ_ENDS is 0 that completed read communiciation *
;* and the value is READ_CODE. *
;*********************************************************************
COMM_INT: PUSH ACC
PUSH PSW
MOV A,TL0 ;================
ADD A,BUAD_RAM_L
MOV TL0,A ;================
MOV TH0,BUAD_RAM_H ;================
JB SEND_READ,READ_DATA ;0 Send or 1 Read
JB RXD_LINE,COMM_NEXT0 ;Read first
CLR SEND_ENDS ;Close send
SETB TXD_LINE
SETB READ_INT
MOV READ_FLAG,#01H ;Start read
SETB SEND_READ
POP PSW
POP ACC
RETI
;******** Send communicating **********
COMM_NEXT0: DJNZ SEND_TIME,COMM_EXIT
MOV SEND_TIME,#03H
MOV A,SEND_FLAG ;Process send flag
CJNE A,#01H,COMM_NEXT1 ;Loop send
MOV A,SEND_CODE
RRC A
MOV TXD_LINE,C
MOV SEND_CODE,A
DJNZ SEND_COUNT,COMM_EXIT ;Loop end
INC SEND_FLAG
POP PSW
POP ACC
RETI
COMM_NEXT1: CJNE A,#00H,COMM_NEXT2 ;Send start bit
CLR TXD_LINE ;1 start_bit low
INC SEND_FLAG
MOV SEND_COUNT,#08H
MOV SEND_TIME,#03H
SJMP COMM_EXIT
COMM_NEXT2: CJNE A,#02H,COMM_EXIT ;Send stop bit
SETB TXD_LINE
INC SEND_FLAG
CLR SEND_ENDS ;completed communicate
SETB SEND_READ ;Setup read status
COMM_EXIT: POP PSW
POP ACC
RETI
;********* Read communicating **********
READ_DATA: MOV A,READ_FLAG
CJNE A,#02H,READ_NEXT1 ;Read a byte
DJNZ READ_TIME,READ_EXIT
MOV READ_TIME,#03H
MOV A,READ_BUFF
MOV C,RXD_LINE
RRC A
MOV READ_BUFF,A
DJNZ READ_COUNT,READ_EXIT ;Completed read
MOV READ_CODE,A ;Write read data byte
INC READ_FLAG ;Setup for next byte
MOV READ_TIME,#02H
POP PSW
POP ACC
RETI
READ_NEXT1: CJNE A,#00H,READ_NEXT2
JB RXD_LINE,READ_EXIT ;Check RXD(RXD_LINE)
first
CLR SEND_ENDS
INC READ_FLAG
POP PSW
POP ACC
RETI
READ_NEXT2: CJNE A,#01H,READ_NEXT3
JB RXD_LINE,CHECK_ERROR ;Check start bit twice
INC READ_FLAG ;Setup for read data
MOV READ_COUNT,#08H
;MOV A,TL0 ;=============
;ADD A,#05H
;MOV TL0,A ;=============
MOV READ_TIME,#03H ;
POP PSW
POP ACC
RETI
CHECK_ERROR: MOV READ_FLAG,#00H ;fail quit
POP PSW
POP ACC
RETI
READ_NEXT3: DJNZ READ_TIME,READ_EXIT ;Wait stop bit
MOV READ_TIME,#03H
MOV READ_FLAG,#00H
CLR READ_ENDS
;CLR SEND_READ
READ_EXIT: POP PSW
POP ACC
RETI
END
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