DATA SEGMENTPORTA EQU 280H		;A端口地址PORTB EQU 281H		;B端口地址PORTD EQU 283H		;命令口地址
DATA ENDSCODE SEGMENTASSUME CS:CODE,DS:DATA
START:MOV	AX, DATAMOV	DS, AXMOV	DX, PORTDMOV	AL, 10010000BOUT		DX,ALMOV	DX, 281H MOV	AL, 00HOUT		DX, ALWAIT1:MOV	DX, PORTAIN	AL, DXAND	AL, 11111111BJZ	WAIT1;从最低位向最高位逐位检验MOV	CX, 8MOV	BL, 1
LP1:MOV	DL,ALAND	DL,BLJNZ LEDSHL		BL,1HLOOP LP1LED:MOV	AL, DL
LP2:MOV	DX,	PORTBOUT		DX,ALCALL DELAYROR		AL, 1		;循环右移JMP LP2DELAY PROCPUSH BXPUSH CXMOV	CX, 04FFFH
DL1:MOV	BX, 00FFH
DL2:DEC BXJNZ DL2LOOP DL1POP CXPOP BXRET
DELAY ENDPCODE ENDS
END START