ID:332149 Altera strongly recommends that you perform SI analysis for the chosen Drive Strength and Output Pin Load combination.

CAUSE: One or more ports violate minimum port rate timing, showing marginal I/O switching performance for the supplied I/O standard and board trace model combination. See the minimum pulse width report for details.

ACTION: Altera recommends that you perform SI analysis for the chosen Drive Strength and Output Pin Load combination to confirm that an acceptable switching threshold is maintained.