MCS－51单片机应用开发实用子程序.rar

				FDS2: 
				MOV 	A,R7 				
				MOV 	R6,A 
				MOV 	R2,#0 				 
				FD21: 
				CLR 	A 				
				MOVC 	A,@A+DPTR 
				XRL 	A,R4 				
				JNZ 		FD22 
				MOV 	A,#1 				
				MOVC 	A,@A+DPTR 
				XRL 	A,R5 				
				JNZ 		FD22 
				CLR 	OV 					
				MOV 	A,R2 				
				RET 
				FD22: 
				INC 		DPTR 				
				INC 		DPTR 
				INC 		R2 					 
				DJNZ 	R6,FD21 				
				SETB 	OV 					 
				RET