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AXI_AD9361 Rest pin

Thread Summary

The user encountered an issue with the AXI_AD9361 output pin 'rst' remaining high after loading a custom bitstream in Vivado. The solution involves deasserting the AXI core reset and configuring the AD9361 ENSM state to move beyond ALERT mode into TX or RX mode using register 0x013. The user found the suggestions helpful and will verify them.
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Category: Software
Product Number: AD9361
Software Version: Vivado 2022.1

Hello everyone:

When I was developing waveforms based on the openwifi project, after initializing the device with the following command, I used Vivado to load my own bit file. Then, I observed that the output pin " rst"  of AXI_AD9361 was always at a high level. By observing the RF signal output by the AD9361 chip with a spectrum analyzer, I found that it was the local oscillator signal and did not modulate the DAC_data I input to the AXI_AD9361 entry.

I would like to know how to configure the registers of 9361 through the serial port tool and which address of the register should be configured to solve this problem?

openwifi Initialization command:
cd /root/openwifi
./wgd.sh
./fosdem.sh

  • HI  

    Thanks for sharing the information.

    If rst is high, it indicates that this bit (active-low reset) remains deasserted—i.e. the core is held in reset.

    • Load your custom FPGA bitstream.
    • Release AXI core reset:
      ////////////////
      axi_reg_write(axi_base, 0x0040, 0x1)////////////////

    Even with AXI reset deasserted, the AD9361 itself stays in alert state unless explicitly told to transition. Registers controlling ENSM are in the AD9361 register map:

    //////////////////////////////////////////////////////////////////////////////////
    iio_reg <device> 0x013 0x01  # Enter ALERT mode

    iio_reg <device> 0x013 0x04  # Move to TX mode (for DAC)

    /////////////////////////////////////////////////////////////////////////////////  

    • Ensure the State machine has moved beyond ALERT and into Tx or Rx.

    Please try these above steps which will help you to resolve.

    Regards,

    SJ

  • Thanks for your reply. Your suggestions have been very inspiring to me. I will further verify them.

    Thank you again.