Stratix V Device Handbook: Volume 2: Transceivers

ID 683779
Date 11/23/2021
Document Table of Contents Lock-to-Reference Mode

In LTR mode, the phase frequency detector (PFD) in the CDR tracks the receiver input reference clock. The PFD controls the charge pump that tunes the VCO in the CDR. The pma_rx_is_lockedtoref status signal is asserted active high to indicate that the CDR has locked to the phase and frequency of the receiver input reference clock.

Note: The phase detector (PD) is inactive in LTR mode.