i'm new with this languaje and with some time testing i can use interrupts with pic16f877a, but not with pic18f4550
can somebody tell me wich is the diference about interrupts between 16f and 18f MCU?
well... two anyway.
PIC16F have a single interrupt vector so if you want to prioritize interrupts you have to do it in software. PIC18F series have two interrupt vectors although you can still use just one if you want. The high priority interrupt can itself interrupt the low priority one but if you want other priorities you still have to implement them in software for one or both vectors.
There are many SOURCES of interrupts, in fact most of the peripherals on the silicon can generate them and there are also external interrupt inputs but only two vectors, high priority and low priority.
I'm not sure what this has to do with TRISD though, the thread sems to have changed title a few messages back.