分支程序结构设计实验报告

分支程序结构设计一.实验目的和要求

1.熟悉运算类指令对标志位的状态影响以及标志位状态的表示方法；

2.掌握条件转移，无条件转移指令的使用方法；

3.掌握分支程序设计，编写，调试和运行的方法；二.实验设备（环境）及要求MASM.EXE LINK.EXE CMD.EXE三.实验内容及步］

1.编写程序，实现将大写字符串转换为小写字符串设字符串的首地址为STRING,字符串长度在LEN单元内数据段定义如下;DATASEGMENTSTRING DBI am a studentLEN equ$-STRINGDATA ENDS

2.从键盘输入一个字符，判断该字符是小写字母，大写字母，数字或其它字符，并给出相应提示四.实验结果与数据处理DATA SEGMENT

1.程序源码:STRINGLEN DBequDATAENDSCODE SEGMENTASSUMEDS DATA,CS CODE；START MOVAX,DATAMOV DS,AXMOV BX,LENMOV AL,OAHMOV[BX],ALMOV AL,$INC BXMOV[BX],ALMOV AH,09HI ama student1$-STRINGLEA DX,STRINGINT21HLEA BX,STRINGMOV CX,LENLOMOV DL,[BX]CMP DL,20HJZ DPADDDL,20HDPMOV AH,02HINT21HINC BXLOOPLOLIJMP LIMOVAH,4CHINT21HCODE ENDSENDSTART运行结果:Microsoft RMacro AssemblerVersion

5.00Copyright CMicrosoft Corp1981-1985,

1987.All rightsreserved.Object filename[TEXT.OBJ]Source listing[NUL.LSI]:Cross-reference[NUL.CRF]:49224+432344Bytes symbolspace free0Warning Errors0Severe ErrorsD:\asmLINK TEXTMicrosoftR OverlayLinker Version

3.60Copyright CMicrosoft Corp1983-

1987.All rightsreserved.Run File[TEXT.EXE]:List File[NUL.MAPI:Libraries[.LIB]:LINK:warning L4021:no stacksegmentD:\asmTEXTI AMfi STUDENTiamastudent

2.程序源码:mydata segmentstringdb1please input a data1,Odh,OAH,shuzi dbis shuzi,Odh,OAH,1$daxie dbis daxie1,0dh,0AH,xiaoxie dbis xiaoxie1,Odh,OAH,!$fqita dbis qita\0dh,0AH,r$fmydata endsmycodesegmentassume csmycode,ds mydatastartmov ax,seg string；mov ds,axmov dx,offset string；mov ah,09hint21h；mov ah,Olhint21h；cmp al,$‘jz exitcmp al,30h；jb qitalcmp al,39h；jb shuzil；cmp al,41hjb qital；cmpal,5ah；jb daxiel；cmpal,61h；jb qitalcmpal,7ah；jb xiaoxiel；shuzil jmp10；mov dx,mov offsetshuzi；ah,int21h；jmp10；09h；xiaoxiel mov dx,movah,int21h；jmp10；daxieloffset xiaoxie；movdx,mov09h；ah,int21h；jmp10；qital movdx,movah,int offsetdaxie；21h；09h；offset qita；09h；10jmp startexit movah,4ch；int21h；mycode endsendstart运行结果U severetrrorsD:\asmlink panduanMicrosoftR OverlayLinker Version

3.60Copyright CMicrosoft Corp1983-

1987.All rightsreserved.Run File[PANDUAN.EXE]List File[NUL.MAP1:Libraries[.LIB]:LINK:warning L4021:no stacksegmentD:\asmpanduanplease input a data:1is shuzipleaseinput a data:a isxiaoxieplease inputa data:A isdaxieplease inputadata:%is qitapleaseinputadata:!is qitapleaseinputadata:。