Table of Contents

Installing Putty on a Personal Machine

PuTTY is a computer application that listens in to our board’s serial output. A serial protocol is one where the data to be transmitted bit-by-bit over a single wire. A number of our labs use that capability so you will need to have it available.

When you program your FPGA board you do it over a USB cable that goes between your computer and the FPGA board. It turns out that there are chips and software on the FPGA board as well as in your own computer so that you can piggyback serial communications over USB. Thus, if your FPGA design is transmitting serial information on its tx_out pin, that will appear on your personal machine on either a COM port (Windows) or a /dev/tty device file (Linux) - having been transmitted to your computer over the USB cable.

The program PuTTY is a piece of software you run on your computer to communicate with that port: (1) anything received on the port will be displayed on the PuTTY screen and (2) anything you type in the PuTTY program will be sent out the port.

If you are on a personal machine you will need to install it, otherwise it is already installed on the lab machines. Follow the directions below to get PuTTY installed.

Windows

1. Download the Windows 64-bit Installer here: https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html

2. Follow the Installation Wizard. We recommend adding the shortcut to your desktop for easy access.

3. You are ready to use PuTTY! Adapt the directions here for help. PuTTY Setup

Linux

1. Open a Terminal Window. You can do this in Linux by searching for “Terminal” within the “Show Applications” widget in the bottom left hand corner.

1. Install PuTTY - to do so run “sudo apt-get install -y putty” in the terminal.

3. To launch PuTTY, run “sudo putty” in the terminal.

4. You are ready to use PuTTy! You can adapt the instructions here PuTTY Setup,to help you get PuTTY configured correctly. Skip ahead to the PuTTy Setup Section. As a Linux user, your serial port will be either ttyUSB0 or ttyUSB1.

Testing Your PuTTY

You can test whether your PuTTY is working by setting it up as detailed above and then programming a NEXYS4 DDR FPGA board with this file.

Once you have programmed the board with this bitfile, every time you push the center button ('btnc') on the board it will print out a message on the serial line saying the putty test worked. If you see the message, all is working. If not, some debugging is in order.