Hi Darrel,
Thanks for your answer.
I have used in my program your examples and routines, but i can't undertand why it don't work for me.
So i need to migrate my project on another pic!
Evidently in the past i don't have use the 16f628 but some other one and i have change it for some issue the i can't remember.
Thanks again for your explanation and for your very good examples scattered for all the forums that help us to live and make code in more easy and strong way! ;-)