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XADC VP VN pin

marcomercuri85

Hi all,

I would like to use the internal XADC. Looking at the schematic, it seems that the PicoZed FMC Carrier Card V2 does not support connections to the VP/VN analog input (JX1.97, JX1.98, JX1.99, JX1.100). Is it that true?

If yes, what should I do to use the XADC? If not, where I can find these pins on the carrier card?

Thanks.

Best Regards,

Marco 

  • 0

    Hi there,

    The PicoZed FMCV2 is not designed for this.  The FMCv2 does not have access to the XADC pins you as designated.

    The PicoZed carrier card was designed to be the best fit for most applications, as the PicoZed was designed to be a product, not a reference board.  We would expect you to generate your own customized Carrier Card.

    If you want to experiment with the XADC pins, as you pointed out in another thread, the MicroZed actually has access to these pins and there are Carrier Cards that have these pins brought out to a header.  The MicroZed kit can actually be run stand alone with only adding either wires or an adapter to gain access to the XADC pins.  If you were to generate a board and intend on using the PicoZed, it might be just as easy to cut a board for the PicoZed - bringing those same XADC pins out to a header / circuit.

    If you are looking for general ADC use, there are many more examples using PMODS - which will directly plug into the PMOD ports on the FMCv2 Carrier Card.  We also have a few examples of using various ADCs with our development boards that you could leverage code/firmware from.  I would suggest this route for experimenting with an ADC coupled with an FPGA.

    --Dan

  • 0

    Hi Dan,

    can I use as alternative the 16 auxiliary analog inputs/digital I/O (DC-250 kHz)?

    If I'm not mistaken they are in bank 35, marked as ADxP, ADxN. For example, 

    F7 -> IO_L1P_T0_AD0P_35
    E7 -> IO_L1N_T0_AD0N_35
     
    Thanks.
     
    Best Regards,
    Marco
  • 0

    Hi there,

    Which SOM are you intending to use?
    Ball F7 is a GROUND on a 7010 based SOM.
    On a 7030, that ball is marked as a AD0P for XADC, which means you could use that.  That signal will end up on the FMC LPC connector.

    Again, depending on your accuracy requirements (Eb/No), due to this signal being routed for DIGITAL not ANALOG on the FMCv2, as well as the amount of support out there, I would again recommend you use an ADC on a PMOD instead of using this pin.

    --Dan