第一节 串行接口与通信
Post on 30-Dec-2015
212 Views
Preview:
DESCRIPTION
TRANSCRIPT
-
(SYNC)ASYNC1
-
0 45678ASCII 1()() 11.52 1
-
120/10101201200/1200
-
2
-
(bit)HDLC()EBCDASCIIIBM(BSC)
-
a b c
-
(1)(2) ABBA(3)
-
1
-
2(MODEM)()
-
(DTE)MODEM(DCE)1RS-232C RS-232CD259
-
RS-232CMODEMRS-232C
-
RS-232C259. TXD2MODEM RXD3RTS*4MODEMCTS*5
-
DSR*6(MODEM) CD8()MODEM RI22MODEMDTR*20RIMODEMGND7
-
RS-232CEIA1-3V~-15v0+3V~+15V EIATTL MCl488TTLEIAMCl489EIAITLRS-232C
-
2RS-423ARS-232CRS-232C1987RS-423A RS-423A
-
3RS-422ARS-422A
-
RS-422A2v0.2v25v
-
4RS-485RS-485
-
12RS-232C3RS-232CTTL4Modem
-
8251A8251A8251A 8251A 8251A8251A
-
8251A8251A8251A10~64K0~19.2K256788251A/
-
35678116641/11152 45
-
8251A
-
1 TXD12
-
CPU8251ATXRDYCPU8CPUTXE
-
2RXDRXD 8251ARXRDYCPU
-
8251ARXDRXD8251ASYNDET
-
SYNDET RXDRXRDY
-
3 CPU8251A38CPU8251ACPU8251A
-
4/(1)8251A(2)8251A (3)/C/ (4)CLK8251A RESET8251A58251A
-
251A
-
1251ACPU CS*CPUD7-D08CPU8251A8251ACPU
-
/RD* CPU8251AWR* CPU8251AC/D*//8251A/RD*WR*C/D*38251A
-
(4) TXRDYCPU8251A TXETXE8251A RXRDY8251ACPURXRDYRXRDY SYNDET
-
28251A(1) DTR*CPU DSR* RTS*CPU CTS*8251A43
-
TXDCPU8251ATXD RXD8251A
-
3 CLK8251A304.5 TXDTXCTXC11664
-
RXD:TXCRXCTXCCLK VCC GND
-
8251ACPU8251ACPU
-
2
-
8251A MOV DX0FFF2H L IN ALDX AND AL02H Dl1 JZ L MOV DX OFFF0H IN Al DX
-
48251A 128251A(3) CPU
-
8251A1 8251A()167/200E2H00E4H11111010B 0FAH00110111B 37H
-
MOV AL 0FAH MOV DX00E2HOUT DX AL 7/2 MOV AL37H OUT DX AL RTS*DTR*
-
2 52H216H7/00111000B 38H10010111B 97H8251A38251A8251ACPU
-
MOV AL38H 2OUT 52HAL 7MOV AL16H OUT 52HAL 16HOUT 52HAL MOV AL 97H OUT 52H AL
-
3 8251A80 8251A52H50HBUFFER
-
MOV AL0FAH 16 OUT 52HAL 72 MOV AL35H OUT 52HAL MOV DI0 MOV CX80 80
-
BEGININ AL52H RXRDY10TEST AL02H JZ BEGIN IN AL50 MOV DXOFFSET BUFFERMOV [DX+DI]ALINC DI IN AL52H TEST AL38H /
-
JZ ERROR LOOP BEGIN JMP EXIT 80ERROR CALL ERR-OUT EXIT
-
48251A
-
CPUTXRDY8251ACPURXRDY8251A
-
STT MOV DX8251A MOV AL7FH OUT DXAL 825lA81 MOV AL11H 64OUT DXALMOV DI MOV CX
-
NEXTMOV DX8251A IN ALDX AND AL01H TXRDY? JZ NEXT MOV DX8251A MOV AL[DI]8251A OUT DXAL INC DI LOOP NEXT HLT
-
SRRMOV DX8251A MOV AL7FH OUT DXAL 8251A8MOV AL 14H 164OUT DXAL MOV DI MOV CX
-
COMT MOV DX8251A IN ALDX ROR AL1 RXRDY? ROR AL1 JNC COMT ROR AL1 ROR AL1 JC ERR
-
MOV DX8251A IN ALDX MOV [DI]AL INC DI LOOP COMT HLT ERR CALL ERR-OUT
-
182512825138251
-
48251716482513FBH/3F8H58251A38.4KHzRTS*CTS*8251A02C0H02C1H71600B/s816H
-
I/OCPUI/OI/O CPUI/O/CPU
-
1/CPU/
-
2/////
-
I/O1CPUI/O CPU(READY)BUSY CPU
-
2I/OCPUI/OCPUI/OCPU
-
/CPU//
-
3.CPU/I/0(M/IO*)1-2/
-
12CPU
-
8255A 8255A8255A8255A
-
Intel 8255AI/OIntel
-
8255A8255A1ABC I/OA8I/O/B8I/OC8I/O4I/O
-
8255A
-
2ABCPU8255ACPU8255AC/AAC4BBC4
-
388255A/CPU8255A4//8255ARESETA0A1
-
8255ACPU1CPUD0-D78RESET8255AABC
-
CS*RD*8255ACPUWR*CPU8255AA1A08255A8255A4ABC
-
8255A
-
2 PA0~PA7 PB0~PB7 PC0~PC7 8255A 8255A0/ABC1/A B2/A
-
10/ABCI/O0
-
21 I/OAB8I/OC6AB20 (1) 1CPC3-PC5APC0-PC2BPC6~PC70
-
1
-
STB*8255AIBFSTBINTRINTRSTBIBFINTEINTEAPC4BPC0 ABSTB* PC4PC2IBFPC5PC1INTR PC3PC0INTE PC41PC21
-
(2) 1
-
OBF*CPU8255A8255AACK*OBF*8255AINTRINTRACKOBFINTEINTEAPC6BPC2 A BOBF* PC7 PC1ACK* PC6 PC2INTR PC3 PC0INTE PC61 PC21
-
32I/OAC5A30B121
-
12 STB* PC4IBFPC5OBF*PC7ACK* PC6INTR PC3(2) 22
-
(3) 2 20 11XXX01T 2011XXX00T 2111XXX11X 2111XXX10X XT10
-
8255A18255A8255AC/18255A8255A
-
8255A
-
1 8255AA0B0C40C40 10010001 91H MOV AL 91H OUT CTRL_PORTAL(2) C//1/
-
/
-
A2 PC4PC6B1PC2 MOV AL0C4H OUT CTRL_PORTAL MOV AL09H OUT CTRL_PORTALPC4A MOV ALODH OUT CTRL_PORTALPC6A MOV AL 05HOUT CTRL_PORTALPC2B
-
23 8255AA0BUFFCPU8088
-
BUSYACKBUSY
-
PC0PC0/PC7BUSY8255A10001000 88H A0C00PC0: 00000001 01HPC000000000 00H8255A400H01H02H03H
-
DADA SEGMENTBUFF DB 'This is a print program!''$'DATA ENDSCODE SEGMENT ASSUME CSCODE DSDATASTARTMOV AX DATA MOV DS AX MOV SIOFFSET BUFF
-
MOV AL 88H A0OUT 03H AL C00MOV AL 01HOUT 03HAL PC0WAIT IN AL 02H TEST AL 80H JNZ WAIT MOV ALSI CMP AL'$' JZ DONE OUT 00HAL A
-
MOV AL00H OUT 03H AL MOV AL 01H OUT 03HAL INC SI JMP WAITDONE MOV AL0DH OUT 00HAL MOV AL 00H OUT 03HAL MOV AL 01H OUT 03HAL
-
WAIT1 IN AL 02HTEST AL 80H PC71 JNZ WAIT 1 MOV AL0AH OUT 00HAL MOV AL 00H OUT 03HAL MOV AL 01H OUT 03HAL MOV AH4CH INT 21H CODE ENDSEND START
-
4 8255A1BUFF100CentronicsPC08255AA8255APC38259AIR3
-
8255A1010XXX0 PC0: 00000001 01HPC0 00000000 00HPC6: 00001101 0DH 8255AA8255A400H01H02H03H8259AICW208H A0BH2CH4
-
MAIN MOV AL0A0H OUT 03HAL 8255A MOV AL01H OUT 03HAL XOR AXAX MOV DSAX MOV AXOFFSET ROUTINTR MOV WORD PTR [002CH]AX MOV AXSEG ROUTINTR
-
MOV WORD PTR [002EH]AX MOV AL0DH OUT 03HAL 8255A A MOV DIOFFSET BUFF MOV CX99 MOV AL[DI] OUT 00HAL INC DI MOV AL00H OUT 03HAL
-
INC AL OUT 03HAL STI NEXT HLT LOOP NEXT HLT
-
ROUTINTRMOV AL[DI] OUT 00HAL A MOV AL00H OUT 03HAL INC AL MOV 03HAL INC DI IRET
-
18255A01228255AA2B
-
38255AA0B1C080H~83H48255AA0B0 8255AA1A0CPU8086A2A1A7A6A5A4A3=101008255A
top related