LVDS SERDES User Guide: Agilex™ 5 FPGAs and SoCs

ID 813929
Date 4/08/2024
Public
Document Table of Contents

5.1.4. Planning the LVDS SERDES Interface

You can let the LVDS SERDES Intel® FPGA IP select the LVDS SERDES pins automatically. If you want to customize the pin selections, plan your LVDS SERDES interface before setting up the LVDS SERDES Intel® FPGA IP. If you want to use differential and single-ended I/O standards in the same or adjacent bank, you may need to customize the pin selections to adhere to the placement restrictions.

The purpose of the following steps is to identify the location of the pin using the Quartus® Prime Pin Planner and Chip Planner tools. Knowing the location of the pins helps you place the LVDS SERDES channel bytes in I/O lanes using the Quartus® Prime Interface Planner tool.

  1. Plan the interface width, the combination of receiver and transmitter channels, and where to place the pins.
    • An LVDS SERDES interface can span across sub-banks but must be within the same HSIO bank. Refer to the related information for valid and invalid scenarios.
    • The channels of the LVDS SERDES interface can be any differential pin pair combinations within the bank and do not need to be sequential.
    • In each HSIO bank, reserve a pair of pins for the reference clock.
    • Refer to the related information about the placement restrictions for differential pins. The placement restrictions guidelines list the pins using the pin index numbers within the I/O bank.
  2. Based on the HSIO bank and pin index numbers you plan to use, refer to the device pin out file to determine the pin names.
    Note: The following steps are optional but recommended. If you are familiar with the device layout, you can use the Quartus® Prime Interface Planner to find the pin location and subsequently the respective I/O lane. You need to run Analysis & Synthesis before you can use the Interface Planner. Refer to HSIO Pin Index Number and Respective Channel Pin Selection to determine which pin channel to select based on the pin index number and I/O lane you plan to use.
  3. In the Quartus® Prime Pin Planner tool, under the Tasks window, double-click Highlight Pins > I/O 12 Lanes.
    The Pin Planner highlights and color-codes the pins according to the I/O lanes.
  4. Using the pin name, locate the pin you want and take note of the I/O lane.

    You need these information later to customize the channel pin selection when setting up the LVDS SERDES IP parameters.

    Figure 18. Pin Planner Showing the Pins According to I/O Lanes


  5. Right-click the pin, and select Locate Node > Locate in Chip Planner.
    The Chip Planner displays the full name and coordinate of the pin.
  6. Take note of the full name of the pin.
    You need this information later to identify the I/O lane where you want to place the channel byte you select in the Pin Settings tab in the LVDS SERDES IP parameter editor.
    Figure 19. Chip Planner Showing the Pin Full Name and Coordinate


  7. Repeat from step 4 for one pin in each I/O lane.
    You only need to locate one pin from each I/O lane.
After completing the procedure, you have a list of pins you want to use and the coordinate of at least one pin in each I/O lane. The pin coordinate helps you to identify its I/O lane in the Quartus® Prime Interface Planner.

The next steps are:

  • Configure and generate your LVDS SERDES IP.
  • Instantiate the LVDS SERDES IP in your design.
  • Run Analysis & Synthesis on your project.
  • Place your LVDS SERDES channel bytes in I/O lanes using the Quartus® Prime Interface Planner tool.