AM335x EVM RGMII doesn't work at 100 Mbps mode

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Posted by Kika

on Feb 15 2012 10:40 AM

Hello,


We are porting Micrium's OS to AM335x with the AM335x EVM.
Everything is going fine but a slight problem with the ethernet.

The RGMII port on the EVM works fine when connected to a PC supporting Gib bit ethernet port.
whereas the EVM port doesn't work(Communication failure) when connected
to a PC supporting only 100Mbps bit ethernet port.

We have ported the Ethernet driver according to the "CPSW Programming Sequence"
given in the AM335x StarterWare user guide.

We can see from the debug window that the 
the Transfer mode is set to "100 Mbps mode, full duplex" with the CPSW_SL_MACCONTROL register.

Note: This problem is not there when we use the TI's SDK with the EVM.

We don't what else should we modify in our software in order make the EVM's ethernet port 
work in 100 Mbps mode.


Is this a problem in the Ethernet PHY placed on the EVM?

Please let me know if there is any link where we could see the datasheet of Atheros PHY.


Regards.

All Replies

Posted by peaves

on Feb 16 2012 01:08 AM

Genius12765 points

The AR8301 data sheet is a restricted document. You must contact Atheros and request a copy of this data sheet.

All three speeds 1000Mbps, 100Mbps, and 10Mbps have been verified using the Atheros AR8301 on the AM335x EVM.

Therefore, there must be a problem with your specific configuration of CPSW.

I will ask someone on our software applications team to offer some suggestions related to your issue.

Regards,
Paul

Posted by Kika

on Feb 16 2012 05:30 AM

Intellectual420 points

hello Peaves,



Thank you so much for considering this issue.

Please let me know if there is any suggestion or 
any thing that we may have to check in our software to troubleshoot this issue.



Regards.

Posted by Schuyler Patton

on Feb 16 2012 09:55 AM

Intellectual2275 points

If you have the Linux SDK installed the phy config code is located in this file in this directory

<installed dir>/linux-<version/board-support/drivers/net/ethernet/ti

The specific function to look at is

cpsw_set_phy_config(....)

I believe this is how the phy is setup for linux, I do not have experience with starterware code or documentation so at the moment I cannot compare to see what the differences are.

Posted by JayWhy

on May 11 2012 12:37 PM

Intellectual330 points

Kika,

I'm looking at doing a port of Micrium's uc/OS-III for the AM335x.

Can you give me an idea of the amount of effort it took for you to do your port? Any tips or recommendations?

Thank you.