Table of Contents
AD7291 FMC-SDP Interposer & Evaluation Board / Xilinx KC705 Reference Design
This document presents the steps to setup an environment for using the EVAL-AD7291SDZ evaluation board together with the Xilinx KC705 FPGA board, the Xilinx Embedded Development Kit (EDK) and the Micrium µC-Probe run-time monitoring tool. Below is presented a picture of the EVAL-AD7291SDZ Evaluation Board with the Xilinx KC705 board.
For component evaluation and performance purposes, as opposed to quick prototyping, the user is directed to use the part evaluation setup. This consists of:
- 1. A controller board like the SDP-B ( EVAL-SDP-CS1Z)
- 2. The component SDP compatible product evaluation board
- 3. Corresponding PC software ( shipped with the product evaluation board)
The SDP-B controller board is part of Analog Devices System Demonstration Platform (SDP). It provides a high speed USB 2.0 connection from the PC to the component evaluation board. The PC runs the evaluation software. Each evaluation board, which is an SDP compatible daughter board, includes the necessary installation file required for performance testing.
Note: it is expected that the analog performance on the two platforms may differ.
Below is presented a picture of SDP-B Controller Board with the EVAL-AD7291SDZ Evaluation Board.
The EVAL-AD7291SDZ 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 AD7291 circuits and reduce design time. When using this evaluation board with the SDP board or BeMicro SDK board, apply +5 V, −5 V, and GND to Connector J2. VDRIVE is supplied by the SDP board or BeMicro SDK board, and VDD is supplied by an on-board regulator
The AD7291 is a 12-bit, low power, 8-channel, successive approximation analog-to-digital converter (ADC) with an internal temperature sensor.
The part operates from a single 3.3 V power supply and features an I2C-compatible interface. The part contains a 9-channel multiplexer and a track-and-hold amplifier than can handle frequencies up to 30 MHz. The device has an on-chip 2.5 V reference that can be disabled to allow the use of an external reference.
The AD7291 provides a 2-wire serial interface compatible with I2C interfaces. The I2C interface supports standard and fast I2C interface modes. The AD7291 normally remains in a partial power-down state while not converting and powers up for conversions. The conversion process can be controlled by a command mode where conversions occur across I2C write operations or an autocycle mode selected through software control. The AD7291 includes a high accuracy band gap temperature sensor, which is monitored and digitized by the 12-bit ADC to give a resolution of 0.25°C.
The AD7291 offers a programmable sequencer, which enables the selection of a preprogrammable sequence of channels for conversion.
- AD7291 Product Info - pricing, samples, datasheet
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.
- FMC-SDP adapter board
- EVAL-AD7291 evaluation board
- Xilinx ISE 13.4 (Programmer (IMPACT) is sufficient for the demo and is available on Webpack).
- uC-Probe run-time monitoring tool
The following table presents a short description the reference design archive contents.
|Bit||Contains the KC705 configuration file that can be used to program the system for quick evaluation.|
|Microblaze||Contains the EDK 13.4 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.|
|uCProbeInterface||Contains the uCProbe interface and the .elf symbols file used by uC-Probe to access data from the Microbalze memory.|
Run the Demonstration Project
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.
At this point everything is set up and it is possible to start the evaluation of the ADI hardware through the controls in the uC-Probe application provided in the reference design.
Launch uC-Probe from the Start → All Programs → Micrium → uC-Probe.
Select uC-Probe options.
- Click on the uC-Probe icon on the top left portion of the screen.
- Click on the Options button to open the dialog box.
Set target board communication protocol as RS-232
- Click on the Communication tab icon on the top left portion of the dialog box
- Select the RS-232 option.
Setup RS-232 communication settings
- Select the RS-232 option from the Communication tab.
- Select the COM port to which the KC705 board is connected.
- Set the Baud Rate to 115200 bps.
- Press Apply and OK to exit the options menu.
Load and Run the Demonstration Project
- Click the Open option from the uC-Probe menu and select the .wsp file from the ucProbeInterface folder provided within the reference design files.
- Before opening the interface uC-Probe will ask for a symbols file that must be associated with the interface. Select the file ucProbeInterface/ADIEvalBoard.elf to be loaded as a symbol file.
- Run the demonstration project by pressing the Play button.
- In some cases it is possible that the uC-Probe interface will not respond to the commands the first time it is ran. In this situation just stop the interface by pressing the Stop button and run it again by pressing the Play button.
- After starting the uC-Probe interface wait until the status of the connection with the board displayed on the bottom of the screen is set to Connected. It is possible to use the interface only after the status is changed to Connected and the data transfer speed displayed next to the connection status is different than 0.
Demonstration Project User Interface
The following figure presents the uC-Probe interface that can be used for monitoring and controlling the operation of the EVAL-AD7291SDZ evaluation board.
Section A is used to activate the board and monitor activity. The communication with the board is activated / deactivated by toggling the ON/OFF switch. The Activity LED turns green when the communication is active. If the ON/OFF switch is set to ON and the Activity LED is BLACK it means that there is a communication problem with the board. See the Troubleshooting section for indications on how to fix the communication problems.
Section B is used to modify the content of Command Register. After any change of the buttons position is necessary to press the Write Command button.
Section C is used to read data from the VOLTAGE and T_SENSE registers. The T_SENSE value is converted and displayed as a value in degrees Celsius.
Section D is used to read data from the VOLTAGE_ALERT_STATUS and T_ALERT_STATUS registers.
Section E is used to modify the Alert Limits' values. After any change of the sliders position is necessary to press the Write Alert Limits button.
In case there is a communication problem with the board the follwing actions can be perfomed in order to try to fix the issues:
- Check that the evaluation board is powered as instructed in the board's user guide.
- In uC-Probe refresh the symbols file by right-clicking on the System Browser window and selecting Refresh Symbols.
- If the communication problem persists even after performing the previous steps, restart the uC-Probe application and try to run the interface again.