Please refer to the Arria® 10 Device Datasheet for the Run Length specification.
In addition, the conditions for CDR to shift from LTR -> LTD mode are as follows, and if these conditions are violated, CDR will shift from LTD -> LTR mode.
(Reference) Arria 10 Transceiver PHY User Guide
https://docs.altera.com/r/docs/683617/21.1/arria-10-transceiver-phy-user-guide/cdr-lock-modes
(5.1.6.3. CDR Lock Modes)
For Refclk required by CDR, select from the pull-down list.
It depends on the protocol, but basically the input Reference Clock used in the TX PLL is connected and used.
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Category: Transceivers
Tools:-
Device: Arria® 10