Thanks to everybody for the assistance.
yes, I need a fixed frequency so I can use the timer tamplate. >> Is this table applicable to pic18f4523 ?
Additional question:
>> what is the purpose of bit_7 ( rd16 ) in the t1con register? How to use it ?
>> what is the purpose odf the RESETFLAG? yes/no in the DT _int ?
Regards,
Ambrogio