Microchip Application Notes:

AN774 Asynchronous Communications with the PICmicro® USART
http://ww1.microchip.com/downloads/e...tes/00774a.pdf

AN774 Source Code (PIC16, PIC17, PIC18).
http://ww1.microchip.com/downloads/e...otes/00774.zip


From Source code ZIP file, Readme18.txt

There are five code examples for the PIC18F452.
They can be applied to any PIC18 part, with minor changes.
Each file has a brief functional description in the header
at the top of the file. They all receive data and transmit
the data back, but do so in different ways to demonstrate
typical applications of the USART.

Here is a summary of the features of each code example:

P18_TIRI.ASM Use interrupts for transmit and receive, Circular buffers, Eight bit data
P18_TPRP.ASM Poll for transmit and receive, Simple buffers, Eight bit data
P18_TWRP.ASM Poll to receive, Wait to transmit, No buffers, Eight bit data
P18_2STP.ASM Poll to receive, Wait to transmit, No buffers, Eight bit data, Two stop bits
P18_PRTY.ASM Poll to receive, Wait to transmit, No buffers, Eight bit data, Even parity bit

Best regards,

Luciano