MCS－51单片机应用开发实用子程序.rar

				FDD1: 
				MOV 	B,A 					
				MOV 	R2,#0 				
				MOV 	A,R7 
				DEC 	A 
				MOV 	R3,A 				
				FD61: 
				CLR 	C 				 
				MOV 	A,R3 
				SUBB 	A,R2 
				JC 		FD69 				
				RRC 	A 					
				ADD 	A,R2 				
				MOV 	R4,A 				
				MOVC 	A,@A+DPTR			
				CJNE 	A,B,FD65				
				CLR 	OV 					
				MOV 	A,R4 				
				RET 
				FD65: 
				JC 		FD68 				
				MOV 	A,R4 				
				DEC 	A 				
				MOV 	R3,A 				
				SJMP 	FD61 				
				FD68: 
				MOV 	A,R4 				
				INC 		A 				
				MOV 	R2,A 				
				SJMP 	FD61 				 
				FD69: 
				SETB 	OV	 				
				RET