inter-board TTK test fails: rx_ready constantly toggles

Hi Julia,

As I understand it, you are trying to interface an A10 device with a CVGX device using TTK. However, you are observing that the CDR is unable to achieve lock-to-data mode (rx_lockedtodata goes low). To isolate any compatibility between the A10 TTK and CV TTK, I would recommend you to do the following:

1. Create simple one channel Native PHY + TX PLL + reset controller design with similar configuratioin in both A10 and CV devices.

2. Using either A10 as TX or CV as TX, send fixed pattern ie 0xBC to the link partner.

3. Ensure that the ppm difference between the TX refclk and RX refclk is within the preset threshold in the Native PHY ie 100ppm.

4. Create Signaltap in both A10 and CV devices and monitor if Native PHY status signals especially the resets, calibration busy, CDR rx_lockedtodata, CDR rx_lockedtoref and ready signals.

5. Based on the signaltap results, we can decide on the next step of debugging.

Regarding your inquiry on the word alignment, for your information, you would need to get CDR to achieve lock-to-data mode first before you can proceed to the next step of performing word alignment. Without lock-to-data, all the data from CDR can be considered invalid.

Please let me know if there is any concern. Thank you.