Arria 10 XVCR oversampling 155Mbps CDR setting

Hi Dlim,

1.Option 1 - you can use CDR manual mode LTR instead of LTD.

Customer have try CDR manual mode LTR, when long length of zero appear on RX PMA, the parallel_rx_data port appear error data.

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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.

155Mbps serial data stream have been scrambled for DC balance and limits the maximum number of consecutive 1s and 0s in the serial data stream from SDH network equipment, so the RX PCS 8B/10B have been disable. Customer will manually do descrambler of receiver data from parallel_rx_data port using used the recovery clock. There must be a long length of zero that are detected on RX PMA because of 10X oversampling(Serial rate is 1.25Gbps), so we want to know how to receive correct data and LTD will not change to LTR with CDR automatic mode when detected a long length of zero on RX?

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3.Option 3 - customer needs to manage his/her data transfer to avoid long length of zero or one

​Customer could not manage his/her data transfer to avoid long length of zero or one because the serial data from SDH network.

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Best Regards

Penn

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