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AD7982 FMC-SDP Interposer & Evaluation Board / Xilinx KC705 Reference Design

Supported Devices

Evaluation Boards

Overview

This document presents the steps to setup an environment for using the EVAL-AD7982SDZ evaluation board together with the Xilinx KC705 FPGA board and the Xilinx Embedded Development Kit (EDK). Below is presented a picture of the EVAL-AD7982SDZ Evaluation Board with the Xilinx KC705 board.

ad7982.jpg

For component evaluation and performance purposes, as opposed to quick prototyping, the user is directed to Analog Devices System Demonstration Platform (SDP). The SDP consists of a:

The EVAL-SDP-CB1Z controller board is part of Analog Devices SDP providing USB 2.0 high-speed connectivity to a PC computer running specific component evaluation software. Each SDP evaluation daughter board includes the necessary installation files needed for this performance testing. It's expected that the analog performance on the two platforms may differ.

Below is presented a picture of SDP-B Controller Board with the EVAL-AD7982SDZ Evaluation Board.

ad7980_sdp.jpg

The AD7982 is an 18-bit, successive approximation, analog-to-digital converter (ADC) that operates from a single power supply, VDD. It contains a low power, high speed, 18-bit sampling ADC and a versatile serial interface port. On the CNV rising edge, the AD7982 samples the voltage difference between the IN+ and IN− pins. The voltages on these pins usually swing in opposite phases between 0 V and VREF. The reference voltage, REF, is applied externally and can be set independent of the supply voltage, VDD. Its power scales linearly with throughput. The SPI-compatible serial interface also features the ability, using the SDI input, to daisy-chain several ADCs on a single 3-wire bus and provides an optional busy indicator. It is compatible with 1.8 V, 2.5 V, 3 V, and 5 V logic, using the separate VIO supply.

The EVAL-AD7982SDZ evaluation board is a member of a growing number of boards available for the SDP. It was designed to help customers evaluate performance or quickly prototype new AD7982 circuits and reduce design time. When using this evaluation board with the SDP board or Xilinx KC705 board, apply +7.5V as +Vs, a voltage between -2V and -5V as -Vs and +2.5V as VDD.

More information

Getting Started

The first objective is to ensure that you have all of the items needed and to install the software tools so that you are ready to create and run the evaluation project.

Required Hardware

Required Software

  • Xilinx ISE 13.4
  • A UART terminal (ex. TeraTerm / Hyperterminal).

Downloads

The following table presents a short description the reference design archive contents.

Folder Description
Bit Contains the KC705 configuration file that can be used to program the system for quick evaluation.
DataCapture Contains the script used to read data from the ADC and save it into a file on the PC.
Hdl Contains the HDL driver for the AD7982 ADC.
Microblaze Contains the EDK 13.2 project for the Microblaze softcore that will be implemented in the KC705 FPGA.
Software Contains the source files of the software project that will be run by the Microblaze processor.

Run the Demonstration Project

Hardware Setup

Before connecting the ADI evaluation board to the Xilinx KC705 make sure that the VADJ_FPGA voltage of the KC705 is set to 3.3V. For more details on how to change the setting for VADJ_FPGA visit the Xilinx KC705 product page.
  • Use the FMC-SDP interposer to connect the ADI evaluation board to the Xilinx KC705 board on the FMC LPC connector.
  • Connect the JTAG and UART cables to the KC705 and power up the FPGA board.
  • Start IMPACT, and double click “Boundary Scan”. Right click and select Initialize Chain. The program should recognize the Kintex 7 device (see screenshot below).

  • Program the KC705 FPGA using the “Bit/download.bit” file provided in the reference design archive.
  • Power the ADI evaluation board.
  • Start a UART terminal and set the baud rate to 115200 bps.

At this point everything is set up and it is possible to start the evaluation of the ADI hardware. To capture data from the ADC run the data_capture.bat script located in the DataCapture folder from the reference design .zip file. Every time the script is run a new batch of 8192 samples are read from the ADC at the ADC's maximum sampling rate and saved into the Acquisition.csv file located in the same folder as the data capture script. On the UART terminal messages will be displayed to show the status of the program running on the FPGA as shown in the picture below.

The first time the data capture script is run it is possible that an error will occur while the script is trying to connect to the system. Just run the script again and the error shouldn't appear anymore.

More information

28 May 2012 15:18
resources/fpga/xilinx/interposer/ad7982.1338212418.txt.gz · Last modified: 28 May 2012 15:40 by Alexandru.Tofan