SYZYGY ADC-LTC226X Reference Design

Note on Carrier Compatibility

We provide gateware for the XEM8320 as an example. Applying the Xilinx example design to other compatible carriers is left as an exercise for the reader. This generally involves applying new constraints and a new target FPGA.

Introduction

This reference design uses FrontPanel with an XEM8320 to obtain data from a SYZYGY ADC peripheral. A host PC running Windows 10 generates an animated graph of the retrieved data. The design is based heavily on Xilinx Application Note 524, XAPP524, and implements a simplified version of the serial LVDS interface described by Xilinx. 

Required Materials

Tutorial

This tutorial guides you through using your SZG-ADC-LTC2264-12 or SZG-ADC-LTC2268-14 with this example reference design. You will accomplish building the gateware and running the graphing utility. 

  1. Turn off your XEM8320. 
  2. Connect a SZG-ADC to port A.
  3. Connect an SMA cable to the SZG-ADC and your analog signal source. An audio source with a voltage less than 2 volts peak-to-peak works well.
  4. Connect your XEM8320 to your host PC with the provided USB cable. 
  5. Power on your XEM8320. 
  6. Follow the “How to Build the Gateware” section below.
  7. Follow the “How to Run the Graphing Utility” section below.

How to Build the Gateware

  1. Open Vivado 2021.1.1 or later.
  2. In the Tcl Console, enter cd <ADC_Sample directory>.
    • Make sure you use forward slashes instead of backslashes for the file structure.
  3. If you are using the ADC-LTC2264-12, enter source project-adc12.tcl to generate the project.
  4. If you are using the ADC-LTC2268-14, enter source project-adc14.tcl to generate the project.
  5. Add the XEM8320 FrontPanel gateware to the Vivado project.
    • This is found in the “FrontPanelHDL/XEM8320-AU25P” folder of the FrontPanel install.
  6. Click ‘Generate Bitstream’ after the project opens.

How to Run the Graphing Utility

  1. Set up your Python environment by following the instructions from the Opal Kelly ‘Programming Languages’ documentation’ under ‘Python API,’ placing the required files into the reference design’s python folder.
  2. Place the generated bitstream from ‘How to Build the Gateware’ in the reference design’s python folder.
  3. Power on the XEM8320.
  4. Run adc_read.py with the name of the bitfile as an argument.
  5. The animated graph is now displaying the analog signal.