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IBIS MODEL for AM35X

Pretesh Mascarenhas
Prodigy 80 points
Other Parts Discussed in Thread: AM3505

Hi ,

I have downloaded the latest Ibis file for the AM3505/17 from TI's website.

I need to carry out a pre placement simulation using Hyperlynx for the GPMC interface as this interface is connected to a multiple devices - FPGA, FLASH, Addr Latch. As such I need to determine the termination requirements if any!

After doing some simulation I concluded that the AM3505 model doesnt quite seem to be working fine - Too many overshoots, Non-Monotonic Rising/Falling edges,Ringing etc

Driving a PRBS pattern out of the AM35x driver, I notice that the output of the driver is very non-monotonic in nature. Overshooting upto even 5 V in a 3V3 system, Ringing etc.

I needed to validate the IBIS Model of the AM3505 to start with so I carried out a simulation using the model of the Tranceiver Chipset SN74AVC24T245ZRG(as seen on the LogicPD Zoom kit)  and the AM3505.

I send a PRBS pattern of bit time 40 ns from the Am3505 to the Transceiver. I found that the same non-monotonic edges and some overshoot.

 

I am also attaching the snapshot of the actual waveform on the Logic PD dev board, using an Oscilloscope. Below is the signal as seen on the Oscilloscope. The design dosnt have any termination resistors etc. Its a simple Point to point connection. This signal is also connected to a Connector to the Motherboard.

 

 

Could someone please confirm that the status of AM3505's IBIS model!

 

Thank you

Pretesh

  • 0
    TI__Intellectual 1280 points

    Pretesh,

    I was able to duplicate your ringing and non-monotonic characteristics with AM3505/17 ZCN IBIS model using typical process corner and probing at pin of tranceiver chip as you did above.  You need to probe at die of tranceiver chip and you will get similar results to oscilloscope snapshot shown above.  See attached simulation.