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

ID 683751
Date 1/27/2022

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3.8. Guidelines: External Memory Interface I/O Restrictions

These I/O rules are applicable if you use external memory interfaces in your design.

Two GPIOs Adjacent to DQ Pin Is Disabled

This limitation is applicable to Intel® MAX® 10 10M16, 10M25, 10M40, and 10M50 devices, and only if you use DDR3 and LPDDR2 SDRAM memory standards.

Table 23.  DDR3 and LPDDR2 Memory Interface Widths and Device Packages Where Two GPIOs Adjacent to DQ Pins Are DisabledThis table lists the combination of Intel® MAX® 10 10M16, 10M25, 10M40, and 10M50 device packages, and DDR3 and LPDDR2 memory interface widths where you cannot use two GPIO pins that are adjacent to the DQ pins.
Device Package Memory Interface Width (DDR3 and LPPDR2 only)
F256 x8, x16
U324 x8, x16
F484 x8, x16, x24
F672 x8, x16, x24

Total I/O Utilization in Bank Must Be 75 Percent or Less in Some Devices

If you use DDR3 or LPDDR2 SDRAM memory interface standards, you can generally use a maximum of 75 percent of the total number of I/O pins available in a bank. This restriction differs from device to device. In some devices packages you can use all 100 percent of the I/Os. The Intel® Quartus® Prime software will output an error message if the I/O usage per bank of that device is affected by this rule.

If you use DDR2 memory interface standards, you can assign 25 percent of the I/O pins as input pins only.