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Isnan's avatar
Isnan
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5 years ago

Parallel highspeed ADC 9248 to DE-SoC board

Hi everyone,
I am doing a simple signal measurement using DEO Nano SoC kit interfacing with the terasic High-speed AD/DA card (AD9248) using NIOS processor.

I believe that ADC pin interfacing is fine and the ADC chip is working, however, I face problems about data reading, they are not valid nor stable.,
I think this is because my configuration as follows, but I am not sure:
1. clock for ADC using pll 20Mhz
2. not adding on chip memory for buffer

here uart01.zip is my full code, any help will be appreciated
thank you

4 Replies

    • Isnan's avatar
      Isnan
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      5 years ago

      hi @JonWay_C_Intel

      Thankyou for your reply.

      yes, terasic have some projects about ADC, I learn a lot from their examples.
      unfortunately, I only find AD9254 documentation for nios processor application, and the 9254 IP file cannot be modified to AD9248.

      from platform design, I set parallel data from ADC as PIO (parallel I/O, width 14 bit) and directly read in c using command "IORD (adc_base, 0)" without on-chip memory as buffer.
      if anyone can confirm, do I have to use on-chip memory to store adc data capture before processed in nios? thank you

      • JonWay_C_Intel's avatar
        JonWay_C_Intel
        Icon for Frequent Contributor rankFrequent Contributor
        5 years ago

        Hi @Isnan Sorry for the delayed response. Did you find a solution? Have you tested with/without on-chip memory? I think you probably need the on-chip if you are not reading from the NIOS fast enough. Else, your ADC will be overwriting its data even before the NIOS is able to read it.