Question

用MCS—51汇编语言编写程序段

用MCS—51汇编语言编写程序段：将数据块从外部RAM地址0800H处传送到内部RAM地址40H开始的单元，传送25个数据后停止传送，并给p1.0口发送低电平示意程序运行完成。

Answer 1

ORG 0000H
MOV R7，#25
MOV DPTR,#0800H
MOV R0，#40H
AGAIN: MOVX A,@DPTR
MOVX @R0，A
INC DPTR
INC R0
DJNZ R7，AGAIN
CLR P1.0
SJMP $
END

Answer 2

ORG 0000H
LJMP MAIN
ORG 0030H
MAIN:
MOV DPTR,#0800H
MOV R0,#40H
MOV R2,#25
LOOP:
MOVX A,@DPTR
MOV @R0,A
INC DPTR
INC R0
DJNZ R2,LOOP
CPL P1.0
SJMP $
END