PHY Lite for Parallel Interfaces Intel® FPGA IP User Guide

ID 683716
Date 8/02/2023
Public

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2.4.1.2. Pin Placement Restrictions

Follow these guidelines to place the PHY Lite for Parallel Interfaces IP group pins:

  1. Assign each lane to only one group. Each group is either mapped to one lane (x8 mode) or two lanes (x16 mode). When using x16 DQS tree, the first lane should be an even lane.
  2. If using termination with calibration, reserve pin 38 or 62 for RZQ. RZQ is a 240 ohm resistor that you attach it to a specific pin as an impedance reference to calibrate driving and termination impedances to avoid signal reflection. One RZQ group can support up to two different output terminations and one input termination. RZQ pin cannot be used as data pin.
  3. No input or bidirectional pins can be placed in the same lane as RZQ.
  4. Place differential data on two adjacent pins. The first pin should be an even pin. The following shows two differential data pins placed on pins 2 and 12, and occupying 4 pins in total. This example uses an x16 DQS tree since the data pins span over two lanes.
  5. Differential refclk is not supported in the same lane as PHY Lite IP for the LVSTL I/O standard.
Figure 10. Differential Data Pin PlacementThis figure shows the placement of differential data pins.