Nexys Video DMA Audio Demo



The audio demo records a 5 second sample from microphone(J6) or line in (J7) and plays it back on headphone out(J4) or line out (J5). Recording and playback are started by push buttons

Features Used

Not Used Used
8 user switches X
8 user LEDs X
128×32 monochrome OLED display X
160-pin FMC LPC connector X
Micro SD card connector X
HDMI Sink and HDMI Source X
DisplayPort Source X
Audio codec w/ four 3.5mm jacks X
6 user push buttons X
10/100/1000 Ethernet PHY X
512MiB 800Mt/s DDR3 Memory X
Serial Flash X
Four Pmod ports X
Pmod for XADC signals X



  • Nexys Video FPGA board
  • Micro-USB cable
  • Nexys Video Power Supply
  • Headphones or Speakers
  • Audio Input device (Aux-In, Guitar, etc.)



Nexys Video DMA Audio Project Repository – ZIP Archive GIT Repo

Download and Launch the Nexys Video DMA Audio Demo

1) Follow the Using Digilent Github Demo Projects Tutorial. Since this is a Vivado SDK Project, you can either directly launch SDK and import the hardware handoff, or you can generate a bitstream in Vivado before launching SDK. Select the hardware handoff options in the tutorial if you don't want to modify the project block design later. Return to this guide when prompted to check for additional hardware requirements and setup.
2) In order to use the demo, you will need to plug in your microphone or aux input into the respective jack on your Nexys Video. Plug your speakers/headphones into the Line Out or HP Out jack.

3) Make sure that your board is plugged into a 12 Volt power supply, turn on your board, and open a serial terminal (such as TeraTerm) on your computer to receive status messages. Setup the serial port to connect to the appropriate port for your board, with a baud rate of 115200. Then return to the Github Project Tutorial to finish programming and running the demo.


You can connect your serial terminal to your board before the board is programmed, this will make sure that you don't miss any startup messages. If the demo is already running, you can restart the demo in SDK to make sure you get these messages.

Using the Nexys Video DMA Audio Demo

1. Controls

Audio playback and recording are controlled by push buttons as below.

Button Function
BTNU record from microphone in
BTNR record from line in
BTNL play on line out
BTND play on headphone out

2. Recording from an input

Press the record button associated with the input you want to record from. Once the recording is activated, the message “Start Recording…” will be sent over UART and the demo will record 5 seconds of audio. If any buttons are pressed during the recording, the message “Still Recording…” will be sent over UART.

3. Playing to an output

Press the play button associated with the output you want to play to. Once the playback is activated, the message “Start Playback…” will be sent over UART and the demo will play 5 seconds of audio. If any buttons are pressed during the playback, the message “Still Playing…” will be sent over UART.