DEFINE Compiler Directive

Abbreviation	DF
Arguments	One or more names (in accordance with the naming conventions of the C language) separated by commas. An optional value may be assigned to each name.
Default	None.
µVision	Options — C51 — Define.
Description	The DEFINE directive defines preprocessor symbols on the compiler command line. This is equivalent to using the #define directive in your program source code. You may use the #if, #ifdef, and #ifndef preprocessor directives to query names defined with the DEFINE directive. Defined names are copied exactly as they are entered and are case-sensitive. Each name may be assigned a value. Note The DEFINE directive may be specified only on the command line. Use the C preprocessor #define directive to define symbols inside a C source file. The DEFINE directive may not be used to define preprocessor macros.
Example	C51 SAMPLE.C DEFINE (check, NoExtRam) C51 MYPROG.C DF (X1='1+5',iofunc='getkey ()')