DESIGN AND IMPLEMENTATION OF UART USING VHDL

PRESENTED BY:

A.Bhanu Swetha 09/455.K.Tirupati Naidu 09/479.K.Suresh 09/472.K.Sneha 09/474.G.Rajesh 09/468

Under The Guidance OfS.Maha Lakshmi

CONTENTS:

Introduction What is UART When do we need a UART How do we use the UART UART Block diagram Features Applications Conclusion

INTRODUCTION:

The objective of this project is to simulate UART using VHDL, a high level language for modeling digital circuits and by using Xilinx foundation.

What is UART?

The UART we have designed consists 2 modules. They are transmitter, receiver.

Transmitter converts the parallel data words into serial data bits and transmits them over the txd line.

The receiver receives serial bits from rxd line and converts them into parallel data word.

The UART (universal asynchronous receiver and transmitter)

Transmits data in frames.

When do we need a UART?

Control the receiving and transmitting time of the data.

Increase the accuracy and decrease the effect of the noise

UART: What it is and how it works:

UART provides the computer with the RS-232C Data Terminal Equipment

(DTE) interface so that it can "talk" to and exchange data with modems and

other serial devices.

As part of this interface, the UART also:

Converts the bytes it receives from the computer along parallel circuits

into a single serial bit stream for outbound transmission

On inbound transmission, converts the serial bit stream into the bytes that

the computer handles

Adds a parity bit (if it's been selected) on outbound transmissions

and checks the parity of incoming bytes (if selected) and discards the

parity bit

• Adds start and stop delineators on outbound and strips them from

inbound transmissions

• Handles interrupts from the keyboard and mouse (which are serial

devices with special ports)

How do we use the UART?

The use of the UART can be confusing at first but is rather straightforward once an understanding of the UART is acquired.

Let us take the UART data format. This implementation of the UART transmits in blocks of 11 bits; 1 leading low start bit, 1 trailing high stop bit, 1 parity bit and 8 data bits.

The UART data format

Start Bit Always 0

Parity bit As per parity selected

Stop Bit Always 1

Data Bits 5-9

UART FRAME:

FOR EXAMPLE:

UART Port

UART Block Diagram:

PINS DESCRIPTION:•UART Registers

•TDR Transmit Data Register

•TSR Transmit Shift Register

•SCCRSerial Communications Control Register

•SCSR Serial Communications Status Register

•RSR Receiver Shift Register

•RDR Receiver Data Register

•UART Flags

•TDRETransmit Data Register Empty

•RDRF Receive Data Register Full

BASIC UART MODULE:

Supports all data rates from 9600 to 921600 baud

Receive and Transmits interrupt flags

Faster performance than industry

8-bit data word with 1 start bit

Features of UART:

The Xilinx foundation system is a development tool that consists of an integrated set of programs to create, synthesis and simulate .

DESIGN SYNTHESIS:

The Language used for programming design for UART is VHDL.

SIMULATION RESULTS:

Transmitter simulation snap shot

Reciver simulation snap shot:

Inter board communications .

Simple PC to Board interfacing.

UART communications.

For all serial communications.

APPLICATIONS:

Interfacing Mouse

Conclusion :

Project mainly deals with the chip level modelling,

taking designing of UART as an example.

During the course of the project it is realized and

experienced the definite advantages that a hardware

description language offers over the conventional

method of designing

THANKYOU

Submitted by:A.Bhanu Swetha 09/455.K.Tirupati Naidu 09/479.K.Suresh 09/472.K.Sneha 09/474.G.Rajesh 09/468