LVDS SERDES User Guide: Agilex™ 5 FPGAs and SoCs

ID 813929
Date 4/08/2024
Public

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4.3.2. DPA Mode

The DPA block selects the best possible dpa_fast_clock from the eight fast clock signals generated by the I/O PLL.

The receiver uses these serial clock signals for the following functions:

  • dpa_fast_clock— writing serial data into the synchronizer
  • fast_clock—reading serial data from the synchronizer, data realignment, and deserializer blocks

In DPA mode, the DPA FIFO synchronizes the retimed data to the LVDS SERDES clock domain. The DPA clock may shift the phase during the initial lock period. To avoid data run-through conditions caused by the FIFO write pointer creeping up to the read pointer, hold the FIFO in reset state until the DPA locks.

Figure 16. Receiver Data Path Block Diagram—DPA ModeIn this figure, all the receiver hardware blocks are active.


Note: In DPA mode, you can place receiver channels of a SERDES instance in both I/O sub-banks. However, you must drive the channels in each sub-bank with different PLLs.