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Altera_Forum's avatar
Altera_Forum
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17 years ago

ALT2GXB to Marvell 88E1112 via SGMII?

hey everyone,

I am trying to find out if there is anything special that I need to use between the GigE outputs from the ALT2GXB to connect to the Marvell 88E1112 or a similar kind of transceiver that accepts SGMII. The ALT2GXB GigE output is SGMII, right?

It doesn't really like to say that explicitly on the megafunction guide (which leads me to wonder), so I would like to confirm from more seasoned altera users that I am going in the right direction.

Matt

4 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    The ALT2GXB Megafunction is not a MAC Core and so does not implement an SGMII function.

    You will need to use a MAC Core (Altera Tri-Speed_Ethernet) and a PCS function to implement SGMII.
  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    Well, I have heard from a coworker that generated packets on the software side of things (in a Nios processor), sent packets through the ALT2GXB megafunction and into an SFP module (that uses the Marvell 88EE111 PHY chip) to send out GigE. There was only 1.25Gbps line RX and TX (and no clock or anything else) between the ALT2GXB and his SFP module, which leads me to think that the SFP (which has the 88e1111 inside) speaks SGMII.

    He got this working connecting ALT2GXB outputs to the SFP, but I want to put a twist on that and use the 88e1112 (which only communicates serially SERDES or SGMII but has much fewer pins than the 88e1111) on my board since the SFP connector is way too large for my space constraints, and connect it to output pins from the ALT2GXB.

    Do y'all think this has a chance of working?
  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    Did you find a solution? I think the SFP speaks SERDES mode, not SGMII. SGMII sometimes includes the clock, but it's not mandatory (meaning clock has to be extracted from the stream).

    I also need to have SGMII protocol using ALT2GXB - no MAC.