STM32MP157FAA1 IBIS model(ibis5_4gbddr3_e_1p35_0c~95c.ibs) issue

[Saran_Ragunathan]

Recently for a design I had used STM32 MPU (part# "STM32MP157FAA1") with DDR3L (part# "NT5CC256M16ER-EK"). For simulating data & address lines from the IBIS model "ibis5_4gbddr3_e_1p35_0c~95c.ibs" in ANSYS for 500MHz frequency the source transmitter eye waveform itself doesn't look proper. Attached the parameter setup and also the eye diagram waveform image for one of the data lines for reference.

What would be the cause of this distorted signal from the source itself? Suggest for any changes if required from the parameter setup point of view.  

[PatrickF]

Hi @Saran_Ragunathan,

You might find some help to setup simulation in AN4803 (High-speed SI simulations using IBIS and board-level simulations using HyperLynx® SI on STM32 MCUs and MPUs)

Usual pitfall is setting up the right PCB stackup as well right model on each side.

Regards.