Why are incorrect IBIS models generated when the "Enable model selector" option is turned off in the Quartus® Prime Pro Edition Software?

Description

Due to a problem in the Quartus® Prime Pro Edition Software version 19.1 and earlier, you may see incorrect IBIS models being generated when the "Enable model selector" option is turned off. This mainly occurs for the I/O pins for the External Memory Interfaces with termination settings. For these I/Os, you will observe only the drive strength and slew rate IBIS model generated instead of the model with termination settings.

Resolution

To work around the problem, turn on the "Enable model selector," which will generate all possible IBIS model values for the I/O selected.