CP316: Microprocessor Systems and Interfacing

Universal Synchronous Asynchronous Receiver Transmitter (USART)

These five USART code examples for the PIC18F452 are from Microchip Technology. 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 for each code example:

Readable Code	Code	Transmit/Receive	Buffering	Packet Definition
P18_TIRI	P18_TIRI.ASM	Use interrupts for transmit and receive	Circular buffers	Eight bit data
P18_TPRP	P18_TPRP.ASM	Poll for transmit and receive	Simple buffers	Eight bit data
P18_TWRP	P18_TWRP.ASM	Poll to receive, Wait to transmit	No buffers	Eight bit data
P18_2STP	P18_2STP.ASM	Poll to receive, Wait to transmit	No buffers	Eight bit data, Two stop bits
P18_PRTY	P18_PRTY.ASM	Poll to receive, Wait to transmit	No buffers	Eight bit data, Even parity bit

 

• Text: Chapter 9 - Addressable Universal Synchronous Asynchronous Receiver Transceiver
• PIC18FXX2 Data Sheet [pdf, 332pp; ©2006 Microchip Technology Inc.]
  • Section 16. Addressable Universal Synchronous Asynchronous Receiver Transmitter (USART)