External Triggering - RFSoC4x2

Hi, I am new to the field. I wonder if there is a way to trigger the RFSoC4x2 device externally. I want to synchronize the DAC channels with some other devices (Not necessarily RFSoC) using an external TTL pulse.

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Hi Lufter,

Iā€™m not really sure what you mean by trigger here. What are you triggering?

The RFSoC4x2 has both a sync and a 1PPS input, which can be used for synchronisation. I answered a question on these ports in this post here.

Josh

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Hi Josh,
Thank you for the response! The RFSoC4x2 is a part of our automatic workflow. There is a master clock in our system that controls when and which device need to perform what action. In the most simple case, there are two child device under the master clock, say a digital out device and a RFSoC4x2. Now consider we want the DAC channel 1 on RFSoC4x2 to output a 60MHz sine wave after it somehow received a 5V TTL pulse from the digital out device in the workflow. Is it possible for me to implement this with the base overlay?

Lufter

Hi Lufter,

Yes this should be possible, although you would need to add in some custom logic to the base overlay to get this to work.

The RFSoC4x2 has a PMOD header that can be used as GPIO, although not at 5V. I think the voltages PMOD use are 3.3V and 1.8V. I would check the 4x2 schematic and PMOD standard to make sure of this before attaching anything to the header.

You would then need to design a custom HDL IP that would read from the appropriate PMOD input, then output a 60MHz sine wave when an input pulse is detected. A simple NCO would do this. You should be able to find HDL code for an NCO online, or use the DDS compiler that ships with Vivado.

Hope this helps.

Josh

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