原创 CodeWarrior 宏定义

                 有时候在程序中会出现

                             EnableInterrrupt；

                             ClearReg0

        我们看字面意思很容易懂它是什么意思，但是一般初学者一般会被它搞晕，为什么就这样一个单词就能表示开中断呢，其实它在头文件中时有定义的，那就是宏定义，这个单词代表的是一些语句，在包含文件里面有定义的，就是方便编程，增加程序的可读性，下面是CodeWarrior 宏定义的解释：

Defining a Macro <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

An HLI assembler macro is defined using the preprocessor directive `define'.

Example:

The macro is invoked in the following way in the source code:

The preprocessor expands the macro:

Example:

/* Following macro clears the registers 0 and 1. */

#define ClearReg0And1 {asm CLR Reg0; asm CLR Reg1}

The macro is invoked in the following way in the source code:

ClearReg0And1;

The preprocessor expands the macro:

{asm CLR Reg0; asm CLR Reg1; };

You can define an HLI assembler macro on several lines using the line separator `\'.

Example:

/* Following macro clears the registers 0 and 1. */

#define ClearR0andR1 {asm CLR Reg0; \

                      asm CLR Reg1}

The macro is invoked in the following way in the source code:

ClearR0andR1;

The preprocessor expands the macro:

{asm CLR Reg0; asm CLR Reg1; };

Using Macro Parameters

An HLI assembler macro may have some parameters which are referenced in the macro code.

Example:

/* This macro initializes the specified variable to 0.*/

#define Clear(var) {asm CLR var}

The macro is invoked in the following way in the source code:

Clear(var1);

The preprocessor expands the macro:

{asm CLR var1 ; };