Why does the phase difference between the P signal and N signal of differential outputs being non-180 degrees in Agilex™ 7 FPGAs F-Series and I-Series board-level simulations?

Description

Due to a problem in the Quartus® Prime Pro Edition Software version 24.2 and earlier, non-180 degrees phase shift between the P signal and N signal of differential outputs might be observed in board-level simulations because tdelay values are included in the IBIS model.

Resolution

To work around this problem, follow these steps:

1. Manually change tdelay_typ, tdelay_min, tdelay_max to NA for all differential output pins in the IBIS file.
2. Restart board-level simulation

This problem is fixed beginning with the Quartus® Prime Pro Edition Software version 24.3.