Copied from a customer query
I have a question regarding the selection of the interface for the 10G signals
From what I understand you will enable 2 of the interfaces to support copper, and the third can be left as is for the SFP+ interface
Is there a preference or selection you can not do for these interfaces?
the question is if we have any limitation for routing and selection of the interfaces in the connectors so we can allocate the interfaces accordingly
I think what you’re asking is, is there a preference for how each three of the 10G ports on UbiSwitch is configured.
There are 3 10G ports on UbiSwitch, port 0, port 9 and port 10.
Ports 9 and 10 can operate one of three modes:
Mode 1: SGMII/1000GBASE-X/2.5GBASE-X
Mode 2: 5GBASE-X
Mode 3: SFI/USXGMII
Port 0 can operate in one of six modes
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
This is a little confusing. To simplify, there are likely only a few of these modes most people will want to use these ports in.
SFI/USXGMII is for connecting to an external 10G SFP Module
SGMII/1000GBASE-X/2.5GBASE-X is for connecting to an external 1G SFP module
SFI/USXGMII is for connect to an external 10G copper PHY chip.
Ports 9 and 10 can be configured easily as a pair on UbiSwitch, by setting the solder jumpers directly on the board JP4 and JP5. The settings for each is shown below.
| JP4 | JP5 | Mode | For use with |
|---|---|---|---|
| 0 | 0 | 1000BASE-X/SGMII Mode | 1G SFP |
| 0 | 1 | 2500BASE-X Mode | 2.5G SFP |
| 1 | 0 | 10GBASE-R Mode | 10G SFP (default) |
| 1 | 1 | USXGMII Mode | External copper PHY |
By default, UbiSwitch is configured to put ports 9 and 10 in 10GBASE-R Mode, for use with an external 10G SFP. However, JP5 can be soldered, which will put ports 9 and 10 in USXGMII mode, for use with an external copper PHY.
Port 0 requires software to configure, and is by default, set to 10GBASE-R Mode.
Therefore, for an application requiring two copper PHYs and 1 10 SFP, it is recommended to use ports 9 and 10 for the copper PHYs, and port 0 for the 10G SFP.
thank you very much for this reply, it answers the question perfectly
– Rephrased from customer email –
What should we do to be able to use a 1G SFP module on port 0?
– 11 September edit –
̶T̶h̶e̶ ̶o̶n̶l̶y̶ ̶w̶a̶y̶ ̶t̶o̶ ̶c̶h̶a̶n̶g̶e̶ ̶t̶h̶e̶ ̶s̶e̶t̶t̶i̶n̶g̶ ̶o̶f̶ ̶p̶o̶r̶t̶ ̶0̶ ̶i̶s̶ ̶t̶h̶r̶o̶u̶g̶h̶ ̶f̶i̶r̶m̶w̶a̶r̶e̶ ̶o̶n̶ ̶t̶h̶e̶ ̶s̶w̶i̶t̶c̶h̶.
It is possible to change the mode of port 0 on UbiSwitch, without needing firmware. It involves changing a resistor. Slightly more difficult that shorting a solder jumper, but still very achievable.
It can be done by soldering a 4.7K resistor on the UbiSwitch module, which can swap it from 10GBASE-R mode to 1000BASE-R mode.
To do this…
Step 1: Identify the four 4.7KOhm resistors on UbiSwitch that control the mode of Port 0. These resistors are R69, R71, R72 and R74.
By default, UbiSwitch ships with R72 and R69 not installed. This puts Port 0 into 10GBASE-R mode (to operate with a 10G capable SFP.
Step 2: Depending on what mode you want Port 0 to operate in, you will need to make amendments to which of these four resistors are installed. Some common port configurations and the required resistors configurates are below.
Port 0 in 10GBASE-R Mode (for 10G/5G/2.5G/1G/100M SFPs) (Factory default)
R69: Not installed
R71: Installed
R72: Not installed
R67: Installed
Port 0 in 1000BASE-X Mode (for 1G/100M/10M SFPs)
R69: Not installed
R71: Installed
R72: Installed
R67: Installed
Difference from Factory settings
Install a 4.7KOhm 0402 resistor in the R72 position
Port 0 in 2500BASE-X Mode (for 2.5G/1G/100M/10M SFPs)
R69: Installed
R71: Not installed
R72: Installed
R67: Installed
Difference from Factory settings
Install 4.7KOhm 0402 resistors in the R69 and R72 positions. Remove 4.7KOhm 0402 resistor in R71 position.
Port 0 in 5GBASE-R Mode (for 5G/2.5G/1G/100M/10M SFPs)
R69: Installed
R71: Installed
R72: Not installed
R67: Installed
Difference from Factory settings
Install 4.7KOhm 0402 resistors in the R69 position.
