Arria 10 Receiver-Transceiver PHY calibration

Hi TerryU,

As I understand it, you have some inquiries related to A10 XCVR RX calibration.

Specific to your inquiry of "What is the actual function of calibration and how does it effect to receiver-phy? I guess that it would effect to PLL optimization. Is it correct?", for your information, after you perform a rate change to the XCVR, a recalibration is required to fine tune the internal parameters of the TX PLL, RX PMA and TX PMA to ensure that they are optimal at your new data rates. This is also to ensure that XCVR blocks will operate as expected at the new data rates. You may refer to the A10 XCVR PHY user guide -> "Figure 284. Recalibration Sequence when the Transceiver Reference Clock or Data Rate Changes" for the blocks that required to be recalibrated after a rate change.

Just would like to check with you when you switch to 3Gbps and perform user recalibration, the RX CDR still unable to achieve lock to data? Or unable to achieve lock to reference as well?

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

Best regards,

Chee Pin

Hi Chee,

Thank you for your reply.

Indeed, recalibration would be necessary. And I have found another register "Rate Switch Flag Register", that manages charge-pump​ setting for CDR. I think, it might effect Rx-PLL also. I will do some further inquire and trial.

Thanks.

TerryU