sca0.asm

上课老师给的8086仿真器

 	ORG 0000H	;2002/01/23 this is a Sxx program of txd
	AJMP START	;txd have av 02/01/21
	ORG 0023H
	LJMP SERVE
	ORG 100H
	txen bit p3.5
START:	MOV SP,#60H
	CLR RS0		
	MOV R7,#0FFH	
	DJNZ R7,$
	MOV 50H,#0AH	;tx-bytes
	MOV 51H,#55H	;tx-buf data/p1
	MOV 52H,#56H
	MOV 53H,#57H
	MOV 54H,#58H
	MOV 55H,#59H
	MOV 56H,#5AH
	MOV 57H,#5BH
	MOV 58H,#5CH
	MOV 59H,#5DH
	MOV 5AH,#5EH
	SETB PSW.1
	SETB PSW.5
	MOV TMOD,#20H
	MOV TL1,#0F3H
	MOV TH1,#0F3H
	SETB TR1
	MOV 87H,#80H
	MOV SCON,#0F0H
	MOV 08H,#50H	;R0,TX-BUF
	MOV 0EH,#00H	;R6,AV
	LCALL BUF1
	SETB EA
	SETB ES
DISCON:	
	LCALL DIS
	MOV R7,#20H
	ACALL XDEY
	CPL p3.4		;WORK POINT
	SJMP DISCON
XDEY:	PUSH 07H
LP2:	PUSH 07H
LP1:	PUSH 07H
LP0:	DJNZ R7,LP0
	POP 07H
	DJNZ R7,LP1
	POP 07H
	DJNZ R7,LP2
	POP 07H
      	DJNZ R7,XDEY
      	RET
SERVE:	CLR RI
	PUSH ACC
	PUSH PSW
	SETB RS0	;Rx in 1 area
	MOV A,SBUF
	XRL A,#00H	;SXX
	JZ IS_ME	
EXIT:	POP PSW
	POP ACC
	RETI
IS_ME:	CLR SM2
	MOV A,#00H	;SXX
	clr txen
	MOV SBUF,A
	JNB TI,$
	CLR TI
	setb txen
RX_COMD:	
	JNB RI,RX_COMD
	CLR RI
IF_RESET:
	JNB RB8,DO_WHAT
	SETB SM2
	LJMP EXIT
DO_WHAT:
	MOV A,SBUF
	CLR C
	CJNE A,#01H,NEXT1	
	AJMP READY_TX
NEXT1:	MOV A,#80H
	clr txen
	MOV SBUF ,A
	JNB TI,$
	CLR TI
	setb txen
	SETB SM2
	LJMP EXIT
READY_TX:	
	JB PSW.1,TX_TRDY
	MOV A,#00H	;no ready
	clr txen
	MOV SBUF,A
	JNB TI,$
	CLR TI
	setb txen
	SETB  SM2
	LJMP EXIT
TX_TRDY:
	MOV A,#02H
	clr txen		
	MOV SBUF,A
	JNB TI,$
	CLR TI
	CLR PSW.1
	MOV A,@R0
	MOV R4,A	;TX-BYTES
	MOV SBUF,A
	JNB TI,$
	CLR TI
	ADD A,R6
	MOV R6,A
	INC R0
TX_DATA:	MOV A,P1		;@R0 
	MOV SBUF,A
WAIT2:	JNB TI,WAIT2
	CLR TI	
	ADD A,R6
	MOV R6,A
	INC R0
	DJNZ R4,TX_DATA
	MOV A,R6	;TX-AV
	MOV SBUF,A
	JNB TI,$
	CLR TI
	setb txen
	SETB SM2
;	inc 79h
	MOV R6,#00H	;CLR AV
	MOV 08H,#50H	;R0,TX-BUF
	LJMP EXIT
BUF1:	MOV 7EH,#09H
	MOV 7DH,#00H
	MOV 7CH,#00H
	MOV 7BH,#0DH
	MOV 7AH,#14H
	MOV 79H,#00H	;Sxx
	RET
;---------------------------------------------------------
DIS:	MOV A,#00H
	MOV R0,#21H
	MOVX @R0,A
	MOV R0,#7EH
	MOV R2,#20H
	MOV R3,#00H
	MOV DPTR,#LS0
LS2:	MOV A,@R0
	MOVC A,@A+DPTR
	MOV R1,#22H
	MOVX @R1,A
	MOV A,R2
	DEC R1
	MOVX @R1,A
	DEC R0
LS1:	DJNZ R3,LS1
	CLR C
	RRC A
	MOV R2,A
	JNZ LS2
	INC R1
	MOV A,#0FFH
	MOVX @R1,A
	RET
LS0:         DB 0C0H,0F9H,0A4H,0B0H,99H,92H,82H,0F8H,80H,90H
	DB 88H,83H,0C6H,0A1H,86H,8EH,0FFH,0CH,89H,7FH,0BFH,8FH
	END