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SN75LVPE4410: PN SWAP for SN75LVPE4410

Part Number: SN75LVPE4410

Tool/software:

Hi TI expert

I got a question about SN75LVPE4410.

we have a CAD request on PN polarity SWAP on TX side and no swap on RX side.

since pcie spec support PN polarity swap, could we desgin per CAD's request?

thanks in advance.

zack

  • Hi Zack,

    Our PCIe redrivers are protocol-agnostic, meaning that they do not measure or interpret the data that they transmit. Therefore, in your example, because RX0P is given a P signal, TX0P will send a P signal, and because RX0N is given a N signal, TX0N will send a N signal, which is the usual operating case.

    On the output side, your example has the redriver output P signal being sent to the TX_RE_TX3N signal on the receiver, and the redriver output N signal is sent to the TX_RE_TX3P signal on the receiver. So the inversion is really happening after the redriver. Because the PCIe receiver is protocol-aware, it should be able to detect the polarity inversion during link training and compensate for it.

    Basically, the situation you have shown here should be OK as long as the receiver is compliant to the PCIe protocol. The redriver itself does not care about how the outputs are wired.

    Best,

    Evan Su