《部分宏汇编初步ppt课件》由会员分享，可在线阅读，更多相关《部分宏汇编初步ppt课件（45页珍藏版）》请在装配图网上搜索。
1、name STRUCfield-declarationsname ENDS 其中，字段为组成构造的各个内部变量，和普通DB/DW等变量的声明是一样的Employee STRUCIdNum DB 000000000LastName DB 30 DUP(0)Years DW 0SalaryHistory DW 4 DUP(0)Employee ENDS000000000(null)00000SalaryHistoryLastnameYearsIdnumCOORD STRUCTX DW?;offset 00Y DW?;offset 02COORD ENDS.datapoint1 COORD poin
2、t2 COORD worker Employee emp Employee NumPoints=3AllPoints COORD NumPoints DUP()CS_Dept Employee 20 DUP()accounting Employee 10 DUP().dataworker Employee mov AX,TYPE Employee;49mov AX,SIZE Employee;49mov AX,SIZE worker;49mov AX,TYPE Employee.SalaryHistory;2mov AX,LENGTH Employee.SalaryHistory;4mov A
3、X,SIZE Employee.SalaryHistory;8Employee STRUC;bytesIdNum DB 000000000;9LastName DB 30 DUP(0);30Years DW 0;2SalaryHistory DW 4 DUP(0);8Employee ENDS;49mov dx,worker.Yearsmov worker.SalaryHistory,2000;first salarymov worker.SalaryHistory+4,3000;second salarymov dx,OFFSET worker.LastNamemov si,OFFSET w
4、orkermov ax,(Employee PTR si).Yearsmov ax,si.Years;invalid operand(ambiguous)位到低位分配位数。macroname MACRO parameter-1,parameter-2,.statement-listENDMINPUT MACRO MOV AH,01H INT 21H AND AL,0FH ENDM定义:.codeINPUT调用:从键盘输入09数字，保管在AL中OUTPUT MACRO charPUSH AXMOV AL,charMOV AH,02HINT 21HPOP AXENDM定义:.codeOUTPUT
5、A调用:从屏幕输出一个字符parametermacrotextargumentreplacesdeclaredinsideconsistsofpassesmacroinvocationstatementgeneratesassemblycode宏、形参和实参的关系:REPT constExpressionstatementsENDMConstExpression 为无符号整数表达式，决议了反复的次数iVal=0REPT 100DW iValiVal=iVal+10ENDM以下的代码产生 100 个DW数据序列：10,20,30,.IRP 形参,statementsENDMENDMIRPC 形参
6、,stringstatementsENDMlENDMIF boolean-expressionstatementsELSEstatementsENDIFIF假设布尔表达式不为0时，相应的语句块被汇编；否那么，汇编其它的语句块。IFE假设布尔表达式为0时，那么汇编举例：p176WriteStr MACRO stringIFB ECHO-ECHO*Error:parameter missing in mWriteStrECHO*(no code generated)ECHO-EXITMENDIFPUSH DXMOV DX,OFFSET stringCALL WriteStringPOP DXENDM假设string参数为空，汇编时显示音讯:
部分宏汇编初步ppt课件
