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Reading data from AD9467 FMC board with ZedBoard

Category: Hardware
Product Number: AD9467-FMC-250EBZ(EVAL-AD9467) and ZedBoard
Software Version: Vivado 2018.3

Hi!

I want to read ADC data from AD9467 evaluation board with an FPGA. The board is connected ZedBoard with FMC connector and I am just using FPGA (PL)  part in ZedBoard(not PS part).

 connection AD9467 Eval board and ZedBoard

I am sampling data with Data Clock Output(DCO) that is one of the output of AD9467 chip. Also this clock runs 250 MHz and both edges(rising and falling) are using. The timing diagram from AD9467 datasheet is below.

data capture timing diagram

Board clock  is coming from output(default) with sine wave type input but also we can use other option like on board oscillator or on board clock generator IC but for now it is set default(https://wiki.analog.com/resources/fpga/xilinx/fmc/ad9467#clock_selection). When I am not connect any sinus signal the clock that runs ad9467 chip must not work but it seems still working. For reading adc data  I am debugging FPGA with ILA in Vivado. When I program the FPGA ILA shows up(if there is no clock I guess ILA must not pop up) and showing some data. How that happens? 

ila

Thanks for your helps.

  • Update V1.1

    I changed clock path to the oscillator on the board. I removed C202 and add C205, C206(100nF) acording to the link(https://wiki.analog.com/resources/fpga/xilinx/fmc/ad9467#clock_selection). After this when I give an analog input to the board or when I do not I see always around  value of 32700 in ILA(same again). In datasheet this is approximately 0 V. I did not changed anything adc configuration with SPI, I leaved out everything in default mode.

    output coding

    After that I monitor clock(CLK) that feed ad9467 and data clock output(DCO) that output pin for capture data. Both of clock is must be 250 MHz however oscilloscope says that 25 MHz. Frequency must be 250 MHz acording to the documents on the internet. Also says that oscillator is in 250 MHz (VCC6-QCD-250M000) but in my board this oscillator is 25MHz(VCC6-QCD-25M000). Because of that *** frequency is 25 MHz but is must be 250 MHz. How it can be happened, or did I miss something?

     This is ADC clock input                                                                           

    clk_in 

     This is ADC DCO output

     clk_dco_out

    After all this how can I read data from ad9467 evaluation board with ZedBoard(only using FPGA, PL part)?

    I can open any idea, website links, example projects, articles...? I am already appretiate it for your replies?

  • Hi,

    Just letting you know we saw your thread and someone will be assigned to it as soon as possible.

    Best regards,
    Iulia

  • Hi,

    So to understand better, you used our reference design and you did changes to it in order not to use the PS anymore? Could you give me some details about it? Just to have a general idea of what's going on.

    What would help me is if I could see a block diagram, or an explication to know where you inserted the ILA.

    Can you tell me what revision this board is? Also to send a picture of the back of the evaluation board? The down-facing side. I'm interested in what's written there.

    Best regards,
    Iulia

  • Hi,

    I  read your reference design for knowledge and started from with nothing. I actually want to interface with adc using just fpga and I have a FPGA  board that has a FMC connector. That is why I do not want to use PS part of ZedBoard.

    In my hdl code I have been just using adc coutput clock (DCO) for sampling data in the both rising and falling edges and register the datas to the registers. After that I just combine to 16 bit signal and I inserted ILA to this 16 bit signal. Just that. 

    Now I changed the clock selection to the clock genereation part and I am dealing with the generating 250 MHz using on board 25 MHz. By the way, When I am Just using the oscillator I read some data, it is okay but in the 25Mhz because of oscillator is 25Mhz and I want to use in high speed.

    Revision of this board is C.

     Regards,

    Mehmet

  • Moving this thread to High-Speed ADCs forum for support regarding this issue with the 25MHz oscillator.

    For the other HDL questions, I will try to help you but keep in mind that the support is limited since your design is a custom one. But first, to figure out with my colleagues from this forum the issue regarding the oscillator.

    Best regards,
    Iulia

  • Hi Mehmet,
    Were you able to get it working? I am trying to do something similar.

  • To reach the 250 Mhz clock, you need to populate the path of ad9517-4 clocking and you have to configure the IC to use VCO. VCO will generate any frequency that you want. To use the VCO you have to connect the 25MHz oscillator with the AD9517-4 Ref clock pins by populating some capacitors. Once this is done, you have to program the d9517-4 from the SPI and make sure to activate the VCO.
    Hope this will help.