New Contributor
Regular ContributorI have also confirmed with the internal team that they have extracted the respective IBIS models through the Quartus IBIS Writer, which is the golden source. The models’ data from Quartus are the same as those from the external web, where the LVTTL 16mA is equivalent to the LVCMOS 2mA. Hence, I would say that the IBIS models and HSPICE models on the web match the golden source.
They have also run simulations to compare the signals across different current strength settings for LVTTL. From the simulation result, we can see that the signals across different current strength settings behave correctly. However, 3.3 V LVCMOS supports only one current strength setting (2mA), so we cannot perform the same comparison.
Anyway, they have also run IV simulations using HSPICE and confirmed that both LVTTL and LVCMOS can meet their respective current strength settings, where the current measured at VOH is higher than the configured current strength setting.
