Use #pragma startup and #pragma exit preprocessor directives to specify a function which executes upon program startup before main( ) is called or program exits ( just before the program terminates). The syntax is as follows:
#pragma startup func_name <priority>
#pragma exit func_name <priority>
The declaration of the function should be as follows:
void func ( void ) ;
priority variable is optional. It is an integer in the range 64 to 255. ( 0-63 are used by C libraries). Highest priority is 0. The functions with higher priorities are called first at startup and last at exit. If priority is not specified, it defaults to 100.
