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dncmrc1's avatar
dncmrc1
Icon for Occasional Contributor rankOccasional Contributor
4 months ago
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Arria 10 GX RX max intra-differential pair skew

I would like to know, in the Arria 10 GX, what is the RX transceiver max allowed intra-differential pair skew. If it is rate-dependent (as likely is) please let me know all the characterized values....
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  • FvM's avatar
    FvM
    3 months ago

    Hi,

    I presume that tolerated maximal intra pair skew is larger than guessed numbers. I see specification of up to 0.4 Tbit skew in HDMI 1.4 spec, expect that Arria 10 transceiver has no problem to decode the signal.

    As far as I understand, Altera doesn't specify RX max intra pair skew. I also don't think that intra pair skew is a primary parameter in receiver  performance analysis. It translates into differential mode pulse distortion and unwanted common mode signal. Related to specified receiver parameters, minimal eye opening is the nearest relevant parameter.

    To determine HDMI compliance, I would either model expected input waveform with maximal skew and check eye opening. Or test receiver performance in real hardware.

    Regards Frank

Ash_R_Altera's avatar
Ash_R_Altera
Icon for Regular Contributor rankRegular Contributor
3 months ago

Hi,

Altera does not publish any numbers for the Rx intra-pair skew. We generally recommend to follow the layout guidelines, perform SI simulations to check for the eye opening, BER failure etc.

In my opinion, it is a function of data rate and board level parameters. As a general practice, people generally follow below rule:

For <= 6 Gbps, <= 10ps

For >10 Gbps, <= 3ps to 5ps

 

Regards