XIO2001: X2001 - PCI Signals - Overshot - Undershot

Andreas Huber

Part Number: XIO2001

Tool/software:

Hello E2E,

I have a question about the PCI-Signals behind the bridge. We have 2x Standard PCI Slots and see a big undershot on the PCIBus (-1,6V). Your XIO2001 datasheet "Absolutely Max Ratings Vil = -0,5V".

My question now,

What is your opinion?

Best Regards

Andreas Huber

10 months ago

0 Brian Zhou 10 months ago

TI__Guru**** 159105 points

Hi Andreas:

Since -1.6v exceeds Absolutely Max Ratings Vil, it could potentially damage the part even if it's low possibility.

but undershoots can result in signal distortions and potentially cause erroneous data transfer or even system malfunctions.

Best

Brian

0 Andreas Huber 10 months ago in reply to Brian Zhou

Prodigy 70 points

Hello Brian,

I think this over- and undershoot also results from our measurement setup. I found nothing in the PCISpec. Do you have such an app note or similar? Or can you give me a hint how should I measure PCI-Signals?

Andreas

0 Brian Zhou 10 months ago in reply to Andreas Huber

TI__Guru**** 159105 points

HI Andreas:

To avoid measurement issue, you need to have short ground from prober to ground.

Most likely , it could be caused by PCB design. I don't think we have app notes for this topic.

Best

Brian

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XIO2001: X2001 - PCI Signals - Overshot - Undershot