TMS320F280049: Why call Device_cal function at the condition of "#ifndef _FLASH" when run using debugger

Part Number: TMS320F280049

Hi Expert,

In F280049 example code, there're below comments. Which confused me are

1. What's the different when code running in RAM and Flash, why just call Device_cal function in RAM?
2. If code running in Flash, could it run using debugger, if yes, why not call Device_cal?

#ifndef _FLASH
//
// Call Device_cal function when run using debugger
// This function is called as part of the Boot code. The function is called
// in the Device_init function since during debug time resets, the boot code
// will not be executed and the gel script will reinitialize all the
// registers and the calibrated values will be lost.
// Sysctl_deviceCal is a wrapper function for Device_Cal
//
SysCtl_deviceCal();
#endif

Thanks!

Best Regards

Rayna