This post provides the solution for using the PIC controller UART interface (e-g to connect PIC controller with PC using serial adapter).
Complete code and simulation can be downloaded from the ‘Downloads‘ section at the bottom of this post. The following figure shows the result of simulation of PIC UART in Proteus7.6.
In the main function UART is intialized by calling the function InitUART (defined in the serial.c file included in the project). Then a Hello World! is sent on the UART terminal (e-g using serial adapter you can display this Hello World! on Hyper Terminal on PC). After that, interrupts are enabled because in the Interrupt Service Routine (ISR) UART interrupt is handled as shown below in the code.
For more detail: Interfacing with UART of PIC microcontroller