ORG 0003H ;STANDARD EXTERNAL INTERRUPT INT0 ENTRY POINT
EXTINT0:
	MOV A,P0
	SETB P3.7 ;HIGH TO LOW TRANSITION TO CLR INTERRUPT LINE AND ENABLE OUTPUT LATCHES
	CLR P3.7 ;NOTE: P3.7 = RD PIN ON 8051
	MOV R5,#0FFH			      
RETI