12.5.3扩展ram到片内ram数据复制.txt

《MCS-51单片机应用开发实用子程序》配套源代码下载

EBCLR2:
MOV	A,ADDPL					
MOV	DPL,A					
MOV	A,ADDPH					
MOV	DPH,A
MOV	A,R7
JZ		EBC21
INC		R6
EBC21:
CLR		A
MOVX	@DPTR,A					
INC		DPTR
DJNZ	R7,EBC21
DJNZ	R6,EBC21
EXRMTORM:
MOV   	 A,ADDPL					
ADD    	A,R7
MOV    	DPL,A
MOV    	A,ADDPH
ADDC   	A,#00H
MOV    	DPH,A
MOV    	A,R0
ADD    	A,R7
MOV    	R0,A
ITEM1:
DEC    	R0						
DEC    	DPL
MOV    	A,DPL
CJNE   	A,#0FFH,ITEM2
DEC    	DPH
ITEM2:
MOVX	A,@DPTR					
MOV	@R0,A
DJNZ	R7,ITEM1
RET