Code in assembly modules can gain access to the special function registers by including pre-defined assembly header files. The appropriate file can be included by add the line:
#include <xc.inc>to the assembler source file and using a .S extension with the source filename to ensure it is preprocessed.This header file contains appropriate commands to ensure that the header file specific for the target device is included into the source file.
These header files contain EQU declarations for all byte
or multi-byte sized registers and #define macros for named bits within
byte registers.