5.10.2.3 Setup Of Device State

Some PIC devices come with an oscillator calibration constant which is pre-programmed into the device’s program memory. Code is automatically placed in the runtime startup code to load this calibration value (see 5.2.9 Oscillator Calibration Constants).

If the software stack is being used by the program, the stack pointer (FSR1) is also initialized by the runtime startup code (see 5.4.2.2.1 Object Size Limits).