Arria 10 XVCR oversampling 155Mbps CDR setting

Hi Penn Tan,

Yes, CDR will loose lock if encounter long length of zero or one data transfer. This is expected behaviour.

As a workaround,

1. Option 1 - you can use CDR manual mode LTR instead of LTD.
2. Option 2 - I am not sure about SDH protocol but Ethernet protocol utilize 8b/10b encoder/decoder in PCS block to address this kind of issue. 8B/10B encoding limits the maximum number of consecutive 1s and 0s in the serial data stream to five. This limit ensures DC balance as well as enough transitions for the receiver CDR to maintain a lock to the incoming data.
3. Option 3 - customer needs to manage his/her data transfer to avoid long length of zero or one

Thanks.

Regards,

dlim