4 Replies Latest reply on Jul 27, 2018 10:15 AM by Carlos_A

    i210 Unused Pins when configuring for 100/10 Mb only

    JRFConsulting Community Member

      I am using a COM Type 10 module that contains an i210 Ethernet controller. I'm designing a carrier board for this COM module and  I desire to configure the i210 as a 100/10 Mb only controller.

      Therefore, the MDI2 and MID3 differential pairs will not be used, only the MDI0/1.  Is it OK to leave these pins unconnected?  If not what is the preferred method for terminating them.

       

      Also, with the i210 controller, it is possible to 'turn-off' the gigabit mode and it will be configured as a 100/10 Mb controller.  How is this done?

      Is there an external software configuration tool used to do this?  If so, what is the name of this tool?

       

      Any help that you can offer would be appreciated.

      Thanks

      Jim

        • Re: i210 Unused Pins when configuring for 100/10 Mb only
          Carlos_A Brown Belt

          Hello, JRFConsulting:

           

          Thank you for contacting Intel Embedded Community.

           

          The information that may answer your questions can be found in section 12.5.5, on page 816 and 817 of the Intel(R) Ethernet Controller I210 Datasheet document # 333016.

           

          We hope that this useful to you.

           

          Best regards,

          Carlos_A.

            • Re: i210 Unused Pins when configuring for 100/10 Mb only
              JRFConsulting Community Member

              Hi Carlos -

              Thanks for the response.

              What does it take to set bit 4 of the Software Defined Pins Control (LAN Base Address + Word 0x20)?

              Setting bit 4 to 1b disables 1000 Mb/s (GbE) operation in all power modes (see Section 6.2.21).

               

              Is there an available tool that can be used to do this?  If so what tool would I use?

               

              Thanks again -

              Jim

                • Re: i210 Unused Pins when configuring for 100/10 Mb only
                  JRFConsulting Community Member

                  Hello again, Carlos -

                  I didn't explain in detail the reason for my original question regarding the unused Gigabit channel pin commitments.

                   

                  We are using an Adlink COM Type 10  in our design.  This module uses your i210 controller.

                  Our system is only designed to function at 100/10 Mb/s, thus we don't need the Gigabit capability.  However, when the adapter is configured for AUTO-NEGOTIATION  using the Adapter Advanced settings, the adapter has much trouble connecting at 100 Mb/s.  Most of the time it does but the time required is very excessive, but when we do connect, the link is very solid.  We do see times where the i210 never connects to 100 Mb/s. If the system is configured using the Advanced Settings to link at 100 Mb/s Full Duplex, it works each and every time.

                   

                  I was hoping that the Auto-Nego Link problem was due to the unused signals not being terminated/biased.  Thus, I have modified our prototype to use the 50 ohm termination resistors on the unused MDI2/3 differential channels.  Unfortunately, it made no difference.

                   

                  So...

                   

                  Configured for Auto Negotiation using Advanced Settings:

                  • The system takes a very long time (in some cases never) to connect at 100 Mb/s.
                  • If a connection does occur, I  check the Win 10 system log and see that the adapter connects at 100 MB Full duplex
                  • I perform a network speed test and find a very robust at about 80 Mb/s download speed.

                   

                  Configured for 100 Mb/s Full Duplex using Advanced Settings:

                  • The system connects quickly at 100 Mb Full Duplex
                  • I perform a network speed test and find a very poor 5 Mb/s download speed.

                   

                  Configured for 100 Mb/s Half Duplex using Advanced Settings:

                  • The system connects quickly at 100 Mb Half Duplex
                  • I perform a network speed test and find a respectable 50 Mb/s download speed.

                   

                  So, what I am trying to resolve is:

                  • Why does the i210 struggle to Auto Negotiate at 100 Mb Full Duplex?
                  • Why does the i210 perform poorly when forced to connect at 100 Mb Full Duplex using the Advanced Settings for the Adapter?
                  • Obviously there is a configuration difference when Auto-Neg sets the adapter to 100 Mb/s and when I force the adapter to 100 Mb/s through the Advanced Settings screen.  What are these differences?

                   

                  Initially, when I realized that the unused differential channels were not being properly biased and terminated, I figured this could very well be the reason for the initial connectivity issues.  However, adding the resistors and bias had no effect on the problem.  Next, I was hoping that if the Gigabit disable bit 4 could be set with an external tool then this could be a solution.

                   

                  Hopefully, all that I have written makes sense and you might have some inside knowledge as to me issues.

                  Any help you can offer would be most appreciated.

                  Jim