Hi NTFS,
First,
Is you programming PIC in assembler(native leanguage for PIC)?
If the answer is NO, then don't worry, Your compiler shall solve it for you.
All PIC microcontrollers have Banks of RAM and Pages of ROM/FLASH. If you is programming in assembler must have it in account.
Example,
At Bank0, in address 0x0A0 is VAR_A and
VAR_A = 0x15
At Bank_2, in adress 0x1A0 is VAR_C and
VAR_C = 0x01
at program....
movlw 0x01
addwf VAR_C,1
then VAR_A = 0x16 and VAR_C = 0x01
Why?
You must TO CHANGE to Bank_2 before.
Good luck
FSio