I want to use DP83867E with UbiSwitch to use all 11 ports, will it work

Hello. I am designing a carrierBoard for the ubiswitch.

I want to use Ports 0,9,10 in SGMII mode and I have selected DP83867ERGZR to be used as SGMII to cooper PHY.

Could You tell me if I could use that PHY? or should I select something different?

DP83867E is a pretty standard 10/100/1000BASE-T PHY with SGMII interface from Texas Instruments.

The 88E6393X has three PHY-less ports that support, Port 0, Port 9 and Port 10.

Port 0 supports:

Mode 1: SGMII/1000GBASE-X/2.5GBASE-X

Mode 2: 5GBASE-X

Mode 3: SFI/USXGMII

Ports 9 and 10 support:

Mode 1: SGMII/1000GBASE-X/2.5GBASE-X
Mode 2: 5GBASE-X
Mode 3: SFI/USXGMII
Mode 4: RGMII
Mode 5: RMII
Mode 6: MII

UbiSwitch puts only the SerDes pins on the stacking headers (see below), meaning you can’t use RGMII, RMII or MII on UbiSwitch. Since DP83867E supports SGMII though, that is not a problem for you.

So, you would need to connect your SGMII ports there.

I was going to go further in detail on this, but actually I think it’s easier if we just make and share an example schematic using the DP83867E for you. This will make your life a lot easier and avoid mistakes.

Give us a few days and we’ll share that for you.

Here is an example schematic showing the SGMII connection between DP83867E and UbiSwitch.

We also offer a free design review service. Once your design is complete, feel free to get in touch with us at info@botblox.org. We can sign your NDA if needed.

Hello. I appllied that schematic and have the following behaviour.

DP83867E link established LED is on (after connecting the cable).
DP83867E link activity LED blinks once a few seconds (it doesn’t blink in sync with any other LED on the switch)
I connect a device to the switch and the device sees the ethernet connection but can’t ping any other device connected to the switch.

I am using port 9 but I have three DP83867E connected to port 0, 9, 10 through SGMII and I would like to use all three with 10/100mb/s devices.

I cut the solder jumper SM1 according to Getting UbiSwitch ports working with a 1G SFP

How should I proceed from now? (both to get working port 9/10 and port 0)

Could you email us the schematic for your design, particularly showing the MAC to PHY connections for ports 0, 9, and 10, so we can review it?

ok. I will send you the design shortly.
I’ll only add that I didn’t notice any traffic on SGMII (with an oscilloscope). So if the switch has to initiate the communication, it doesn’t happen.

Got it. We’ll review that now.

It’s either…

  1. A PHY_ID issue on the DP83867
  2. A routing or PCB trace issue (please confirm you’ve done length match and matched impedance)
  3. A mismatch between the PHY setting on UbiSwitch and the DP83867. That would require a firmware update on the UbiSwitch. Thankfully we are actually in the process of doing that.

We will review and get back to you soon.

Thanks for your patience, the new update has now been released. Let me explain how it works.

As you know, we are dealing with the backplane mode on ports 0, 9 and 10 on UbiSwitch. The type of communication used is called the PCS, or Physical Subcoding Layer. Previously, only two modes were possible to be set, 10GBASE-R (for 10G SFP modules) and 1000BASE-X (for 1G SFP modules).

The new software update now allows the following PCS modes to be set using the command line interface.

  • 1000BASE-X
  • SGMII
  • 2500BASE-X
  • 5GBASE-X
  • 10GBASE-X
  • USXGMII

You are using the DP83867E, which uses SGMII. Previously this did not work with 1000BASE-X mode, which is expected. We now need to set the ports to operate in SGMII mode, which is finally possible with this software update. To do this, first you need to update the software running on your UbiSwitch module.

Follow the steps here to do the update process. If you need assistance, let us know.

Once UbiSwitch has been updated with the latest software, you can now use the new features on the command line interface. A list of all the available commands is here. Of most interest to you is “Change PCS mode on SERDES ports”. The command structure is below.

[port ] mac [mode {“1000basex”, “sgmii”, “2500basex”, “5gbaser”, “10gbaser”, “usxgmii”}]

Using this, you will set the ports to SGMII mode, and then the external PHYs should work.

Please keep us posted and let us know if you need any assistance!