RFSoC 4x2 CMAC_Intro

Running PYNQ 3.0.1 on the RFSoC 4x2 device with the unmodified base overlay.
I bought a loopback module to run the CMAC_Intro notebook.
The loopback module is below:

Amphenol SF-100GLB0W00-0DB QSFP28 Loopback Adapter Module, 100 Gb Ethernet, 0 dB Insertion Loss, 0W Power

When running the CMAC_Intro notebook (notebooks/base/board/CMAC_Intro.ipynb) I get a “Receive Channel not aligned error.” when running the blocks

base.cmac.internal_loopback = 0

The error is shown below:

RuntimeError Traceback (most recent call last)
Input In [5], in <cell line: 1>()
----> 1 base.cmac.start()

File /usr/local/share/pynq-venv/lib/python3.10/site-packages/pynq/lib/cmac.py:598, in CMAC.start(self)
596 self.register_map.conf_tx = 1
597 return
→ 598 raise RuntimeError(“Receive channel not aligned”)

RuntimeError: Receive channel not aligned

Any ideas on what could be the problem? Thanks!

Hi @drew,

Welcome to the PYNQ community.

When you plug in the QSFP28 loopback module, does the QSFP presence LED turn on (just below the QSFP cage)?

Does the internal loopback work?

base.cmac.internal_loopback = 1


1 Like

Thanks Mario. Unfortunately the error message is accurate to what was physically happening. It seems the QSFP28 transceiver wasn’t properly aligned and it bent the pins of the connector. Yikes! We’ll have to have the board repaired!

@drew sorry to hear that. Hope the repair goes well.