Chapter 10 Writing Assembler Control Statements
Identifier Definement 187
10.3.1 #define
Syntax
#define [replacement_string] [; comment]
Functional description
This directive causes the assembler to replace the identifier with the replacement_string on all further
lines.
The #define directive differs from the #equ directive in that a string can be specified. Furthermore,
when used in conjunction with the #undef directive, redefinition is possible.
Coding rules
Any string can be coded for the replacement_string. The string can include spaces and tabs. If the
replacement_string is omitted, the identifier will be defined as a null character.
Everything after a semicolon (;) is considered a comment. Therefore semicolons cannot be included in
the replacement_string.
The same identifier cannot just be redefined with another #define directive. When used in conjunction
with the #undef directive, redefinition is possible. Refer to section 10.4, "#undef", for details.
If the replacement_string is omitted, the identifier will be defined as a null character.
Usage example
Source file contents are shown below. The first line replaces data with the character 5. The next line is
an example of changing a mnemonic, so mov data,D0 can be coded as load.
#define data 5
#define load mov data, D0
_CODE section CODE, PUBLIC,2
main
mov data, D0
load
end
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