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DS320PR412-421EVM: DS320PR412-421EVM

Richard Cantong
Prodigy 25 points
Part Number: DS320PR412-421EVM

Hi,

Good Morning!

I am having issues in improving the margin in Upstream Channel 0, it seems that whatever change I make in the EQ Boost and EQ DC Gain, it doesn't affect the eye diagram for Channel 0. It is not the same with Channel 3, where the eye diagram is improving when I increase the EQ Boost. Can you help me check what could be the possible issue?

Background of the PCIe Gen5 Setup:
MotherBoard: Supermicro X13
Redriver card: TI DS320PR412-421EVM (I2C controlled by Aardvark using SigCon Architect 3.2)
Downstream card: Broadcom PEX89xxx card

Upstream Eye diagram when Broadcom card is directly connected to the MoBo:

Upstream Eye diagram when the DS320PR412-421EVM card with default setting is in between.

Upstream Eye diagram when the Ch3 EQ Boost is increased to EQ Index 10.

Upstream Eye diagram when the Ch0 EQ Boost is increased to EQ index 10.


Thanks,
Richard

  • 0
    TI__Guru* 93650 points

    Hi Richard,

    Typically we expect eye height to increase when you change DC gain but you are not able to do so.

    Is it possible for you to run compliance pattern? This way we can put scope at channel 3 and then we can observe and debug this on scope.

    My colleague Evan Su may have additional comments.

    Regards, Nasser.