Intel® MAX® 10 General Purpose I/O User Guide

ID 683751
Date 1/27/2022
Public

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3.10. Guidelines: Clock and Data Input Signal for Intel® MAX® 10 E144 Package

There is strong inductive coupling on the Intel® MAX® 10 E144 lead frame package. Glitch may occur on an input pin when an aggressor pin with strong drive strength toggles directly adjacent to it.

PLL Clock Input Pins

The PLL clock input pins are sensitive to SSN jitter. To avoid the PLL from losing lock, do not use the output pins directly on the left and right of the PLL clock input pins.

Data Input Pins

Potential glitch on the data input pin, leading to input read signal failure, can occur in the following conditions:
  • The output pin directly adjacent to the data input pin is assigned an unterminated I/O standard, such as LVTTL and LVCMOS, with drive strength of 8 mA or higher.
  • The output pin directly adjacent to the data input pin is assigned a terminated I/O standard, such as SSTL, with drive strength of 8 mA or higher.

Intel recommends that you implement these guidelines to reduce jitter on the data input pin:

  • For unterminated I/O standards, implement one of these guidelines:
    • For the directly-adjacent output pin with these unterminated I/O standards, reduce the drive strength as follows:
      • 2.5 V, 3.0 V, and 3.3 V—reduce to 4 mA or below
      • 1.2 V, 1.5 V, and 1.8 V—reduce to 6 mA or below
    • Assign the pins directly on the left and right of the data input pin to a non-toggling signal.
    • Change the data input pin to a Schmitt Trigger input buffer for better noise immunity. If you are using Schmitt Trigger input buffer on the data input pin, you can use the directly-adjacent output pin with unterminated I/O standard at a maximum drive strength of 8 mA.
  • For terminated I/O standard, you can use only one pin directly on the left or right of the data input pin as toggling signal, provided that you set the slew rate setting of this pin to “0” (slow slew rate). Otherwise, assign the pins directly on the left and right of the data input pin to a non-toggling signal.