The Universal Asynchronous Receiver Transmitter $($UART$)$ is a subsystem that is found on nearly every

microcontroller available today. It is used to transfer parallel data between the microcontroller and the PC $($or other

system$)$ in a serial form. The data is assembled into a frame consisting of start bits, data bits, parity bits, and stop

bits. These bits are transferred at an agreed rate $($baud rate$)$ between the devices. It is known as asynchronous

since there is no clock signal transmitted with the data; each side has their own clock which is running at the

expected baud rate. The physical connection typically consists of $3$ pins Transmit $($Tx$),$ Receive $($Rx$)$ and Ground

$($gnd$)$ allowing for full duplex communication. The connection is made between the $$serial ports$$ of the devices

according to the RS$232$ standard which defines the physical connection $($plugs etc$),$ the electrical signals $($voltages$,$

currents$),$ and the protocols $($frame format$)$ used. On the PC the serial port is known as a COM port $($short for

communications port$)$ and will be designated as COM$1,$ COM$2,$ COM$3$ etc

The Tiva Launchpad has $8$ on$-$board UARTs which are connected to different GPIO pins on the microcontroller.

In this laboratory we will be using the serial port on the Launchpad to communicate with the serial port on the PC$.$

However, the physical connection will be via a USB cable rather than the standard RS$232$ cable and interface.

This is only possible on UART$6$ on the Launchpad hence this experiment will use UART$6($Wed$)$ or UART$6($Thu$).$

It should be noted that since there is no physical RS$232$ connection then a $$Virtual Serial Port$$ needs to be set up

on the PC$$s side. This virtual COM port can be seen in the device manager on the PC$.$ The advantage of this is

that we do not need any RS$232$ cabling since the board is supplied with a USB cable. This USB capability is NOT

available on all development boards.

The PC will be running a terminal program called Teraterm. The purpose of this program is to emulate a terminal

which consists of a screen and a keyboard. In this case the screen is a window and the keyboard is the PC$$s

keyboard. The window is used to display the characters received by the PC and the keyboard is used to generate

the characters that the PC will send. this is for keil uvision c with a TM$4$C$1294$ board. The System Clock is $80$MHz$.$ The UART should use the system clock to derive it$$s baud rate.

$$ You will need to preserve the contents of any of the registers used in your functions

$$ All serial communications is done WITHOUT FLOW CONTROL. Make sure this is set up in tera term and

the COM port if required.