• State
  • Replies 5 replies
  • Subscribers 33 subscribers
  • Views 56 views
  • Users 0 members are here
Support feedback
Options
Options
Related

Original question:

DP83869HM: Straps-only configuration possible in 1000 Mbps Media Converter mode with the DP83869 at all?

DP83869HM: "SERDES-to-Copper Mode" possible?

d b
Prodigy 20 points
Part Number: DP83869HM
Other Parts Discussed in Thread: DP83869,

Tool/software:

Hello,

I'm building an SFP module with the DP83869 and I'm trying to figure out if it can be done using straps only.

The DP83869 needs to be configured as a SERDES to copper interface.

The closest description to that setup seems to be Figure 8, "SGMII-to-Copper Mode" on page 10 of SNLA318, however of course the SGMII side would need to be fixed 1000Mbps FD, no auto-negotiation.

Looking at Table 16, "Strap Functional Table for Copper Interface" on the same page seems to indicate that a Forced 1000M, full duplex mode is not available.

So am I correct in understanding that this configuration is not achievable through straps only? Can it be achieved by software? On page 37 of SNLS614D it's stated that "The SGMII Auto-Negotiation process can be disabled and the SGMII speed mode can be forced to the MDI resolved speed. The SGMII forced speed mode can be enabled with the MDI auto-negotiation or MDI manual speed mode. SGMII Auto-Negotiation can be disabled through the SGMII_AUTONEG_EN register bit in the CFG2 register (address 14h)." Would that be enough?

Out of curiosity, would the media converter mode (1000Base-T to 1000Base-X) work in this situation? The linked thread seems to indicate it would, but I have a DP83869 configured like that and while the link is up at 1000M, there's no traffic. The computer reports it's "connected", but with a "self-assigned IP". Would this be an alternative configuration that can be made to work?

Thanks,

  • 0
    TI__Guru**** 178126 points

    Hi,

    For the SFP, is it a Optic Fiber? DP83869 can do 1000Base-FX to 1000Base-T or 100Base-FX to 100Base-TX . Please see table 7-12 in datasheet for bootstrapping settings.

    Can you share a block diagram of your testing setup? How do you connect the 1000Base-T or 100Base-TX?

    Thanks

    David

  • 0 in reply to David (ASIC) Liu
    Prodigy 20 points

    Thanks for the reply.
    The SFP is copper (RJ-45).

    Please find the block diagram below.

  • 0 in reply to d b
    TI__Guru**** 178126 points

    Hi,

    Looking at the KSZ9477S datasheet, the SGMII port has two modes of operation: SerDes mode (which supports 1000BASE-X fiber) and SGMII mode. So depends on the KSZ9477S configuration, you can configure DP83869HM either

    1. 1000BASE-X to Copper Media Convertor Mode

    2. SGMII to Copper Mode.

    Please see this app note on the different configuration mode of DP83869.

    Thanks

    David

  • 0 in reply to David (ASIC) Liu
    Prodigy 20 points

    Right, thanks.

    I have it up and running in 1000BASE-X to Copper Media Convertor Mode, however despite the link being up at 1000M, no traffic flows. I keep getting a "self-assigned IP" report from the computer.

    Please find my configuration below.

    PHY Strap Table
    RX_D0=PHY_ADD[1:0]=0 (def)
    RX_D1=PHY_ADD[3:2]=0 (def)
    OPMODE[2:0]=4 (1000Base-T to 1000Base-X) »
    JTAG_TDO/GPIO_1=OPMODE[0]=0 (def)
    RX_D3=OPMODE[1]=0 (def)
    RX_D2=OPMODE[2]=1
    LED_0=ANEG_DIS=1 (Fiber Force Mode » No AutoNeg on 1000BASE-X side)
    ANEGSEL_[1:0]=3 (Copper side: Auto Negotiation (1000 Advertised, Auto MDIX)
    LED_2=ANEGSEL_1=1
    LED_1=ANEGSEL_0=1
    (see https://e2e.ti.com/support/interface-group/interface/f/interface-forum/1536741/)

    Any tips would be appreciated.

    Thanks,

  • 0 in reply to d b
    TI__Guru**** 178126 points

    Hi,

    Can you please share your schematic, and also register dump 0x00000 to 0x001F, and 0x006E? 

    Can you also check your DHCP server configuration? If the OS is configured to receive an IP from the DHCP server and then not able to receive it, it will then self assigned an IP address.

    Thanks

    David