ContributorAgilex 5 GTS PMA/FEC Direct Loopback
Say I need to connect an oscillating component (with parallel data) to the GTS from the fabric, and then loop it back to via serial in fabric, and then read the output parallel data.
To set this up, can I simply:
1: Set the "TX/RX Common PMA Options Loopback mode" to "parallel"
2: Route `i_rx_serial_data` back to `o_tx_serial_data`
assign gts_i_rx_serial_data = gts_o_tx_serial_data; assign gts_i_rx_serial_data_n = gts_o_tx_serial_data_n;
3: Connect an oscillating component to the `rx_parallel_data`?
Of course I have omitted many signals here, but is it along the right lines?
Many thanks!
Hi,
Thanks for your update.
Based on your description, it seems your datapath is structured as follows:
Oscillator → tx_parallel_data input → GTS PHY → rx_parallel_data output → DMA → HPS
To achieve this setup, you can enable the Parallel Loopback path (Path B). This configuration allows the parallel data fed into the TX interface to be directly routed to the RX interface, bypassing the serializer, deserializer, and CDR blocks.
This approach should help simplify your testing or validation process without involving the full high-speed serial path.
Let me know if you need further clarification or assistance.
Best regards,
Chee Pin
