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Altera_Forum's avatar
Altera_Forum
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16 years ago

max CID length for transceivers

Does anyone know what is the max CID (consecutive identical digits) length the CDR can tolerate before it loses its lock on the incoming data? I've been reading through the docs for the Stratix IV t...
Altera_Forum's avatar
Altera_Forum
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16 years ago

I found, that the Stratix IV datasheet is specifying a run length violation decoder in detail. You may want to read the datasheet more thoroughly. There's also a typical run length specification of 80 without additional explanation. I understand, that the CDR circuit is able to handle run lengths in this order of magnitude. As a prerequisite, the Stratix IV receiver can be configured for DC coupling, so the data stream can be unbalanced.