ZCU111 RF custom signal symbol generation

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1

Hello!

My requirement is simple: using the ZCU111 high-speed DAC output custom signal which doesn’t need the QPSK signal. But I have not seen the example. So follow the RFSoC Workshop example (RFSOC-QPSK) and try to modify it.

  1. My question is which function defines the signal sequence?
  2. By the way, I tried that QPSK example and connect the DAC port to the oscilloscope. In the running process, I have not seen the signal output. I don’t know why.
    Thank you!

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1 Like
2

Hi there,

The rfsoc_qpsk demo comes from this repository. The qpsk symbols are actually generated as part of the hardware design, so you would have to rebuild the overlay with a new signal generator.

To the 2nd point, was the demo working with the loopback cable on the board? If it works on the board, perhaps something was not configured correctly with the oscilloscope setup?

Thanks
Shawn

3

Hi, there,

Thank you for your answer. I have seen the layout of the QPSK example. It looks like using qpsk_tx(hardware) to generate the symbols and using the DMA to store the symbols(below picture shows).

  1. If I could control the DMA directly? and write the data inside? (PYNQ DMA function)

Thank you!

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1 Like
4

I think those DMAs are just used to intercept the data for analysis in Python (they don’t get transmitted). The actual data that is being transmitted to RF comes from the qpsk_tx and goes into that interpolate_logic block and further down the chain.

You would probably have to modify the qpsk_tx IP in MATLAB or add your own DMA that you would write the data to.

Thanks
Shawn