Limit i225-LM to 1Gbit via NVM EEPROM?

[ulfhei]

We use the Intel i225 on one of our own motherboards/COM Express carrier boards, but because of the Ethernet transformer we currently  use is not yet certified for 2.5Gbit, we need to limit its top speed to 1Gbit.

Should it not be possible to do this by programming one ore more flags in the configuration EEPROM?

In the document 596659-Intel-Ethernet Controller-I225-I226-Datasheet-rev2.7 there is information regarding a register in the NVM EEPROM, named "5.1.1.10 Initialization Control Word 2 - 0x000F" (page 29), where there are three bits:

2 EEE_2_5G_AN      Report EEE 2.5G capability in Auto-negotiation.

1 EEE_1G_AN          Report EEE 1G capability in Auto-negotiation.

0 EEE_100M_AN     Report EEE 100M capability in Auto-negotiation

What we want to do is prevent the chip to report the 2.5G capability, so it is only limited to 1G and 100M.

However, I have tried setting the first flag (EEE_2_5G_AN) to both 1 and 0, and it does not affect anything, is still autonegotiates and runs at 2.5Gbit anyway. 

Is this a known problem, so that the bits are not properly working, or is there another part of the EEPROM that needs to be configured for these restrictions to apply?

[Hayat]

Hi ulfhei,

Thank you for posting in Intel Communities.

Since the inquiries related to Programming or Embedded Products we will proceed to move the thread to Embedded Connectivity Community forum,

Thus, we will proceed to close the thread here.

Regards,

Hayat

Intel Customer Support

[CarlosAM_INTEL]

Hello, @Hayat:

Thank you for contacting Intel Embedded Community.

This forum does not state that it is related to an Embedded platform.

You need to consider this previously to transfer this case to the channel that you mentioned.

Best regards,

@CarlosAM_INTEL.

[ulfhei]

OK, so back to the first forum then, or is there a more fitting forum?

[ulfhei]

There has been no reply at all to this topic for a month now, how can we plase proceed with this issue?

[ulfhei]

Another week has passed with no reply, it is now 5 weeks without as much as a peep!

Seriously, I have now as a hardware professional started at least 5 separate support requests, and not even one of them has received any help, they have either been ignored, like this one, or been shuffled around to other forums without a decent reply, or there has been request for more information that I have been unable to provide in time, and then closed down.

So far, my experience with these forums is extremely disappointing and frustrating, is there any other way to get support that is competent and able to provide the in depth information that hardware professionals like me require?