One of the main considerations with application code in ROM is the way in which the application initializes itself and starts executing. If there is an operating system present, this does not cause a problem because the application is entered automatically through the main() function.

No automatic initialization takes place on RESET, so the application entry point must perform some initialization before it can call any C code.

Typically, the initialization code should carry out some or all of the following tasks:

These items are described in more detail below.