Using PRUSS port as RGMII port in AM4377 IDK board

Krishna Prasad

Other Parts Discussed in Thread: AM4377

Hi,

I am trying to bring-up RGMII2 port on AM4377 IDK board.

To achieve this we have done Hardware wise changes (RGMII2 pins to connected to one of PRUSS PHY port). Also Software wise configurations modified.

Now RGMII2 interface is listing on ifconfig command Tx flow is working. Tx statistics incrementing. Also verified TX packets in Wireshark

But Rx flow is not working. In Statistics Rx packet count is zero. RGMII cpsw Driver not getting Rx interrupt. When we checked the RX data line, Data line is toggling.

What might be the issue.

Thanks and Regards,

Krishna

over 9 years ago

0 Patrick OFarrell over 9 years ago

TI__Mastermind 31600 points

Krishna,

I have moved your post to the Sitara Processors Forum so that it can get visibility from the experts.

Patrick

0 Biser Gatchev-XID over 9 years ago

TI__Guru**** 393215 points

Hi,

Are you trying to say that you wired one of the PRU Ethernet PHYs to the CPSW RGMII2 pins? Are you aware that PRU Ethernet PHYs are 10/100Mbit? RGMII interface is 1000Mbit.

0 Biser Gatchev-XID over 9 years ago in reply to Biser Gatchev-XID

TI__Guru**** 393215 points

If you want an AM437X board with two CPSW Gigabit Ethernet ports, I suggest you get a Starter Kit: www.ti.com/.../tmdxsk437x

0 Krishna Prasad over 9 years ago in reply to Biser Gatchev-XID

Intellectual 270 points

Hi Biser,

Thanks for the reply.
I will use RGMII interface with 100Mbit speed.(Use RGMII as RMII). I probed the RX and TX clock and confirmed that Speed is 100MHz(Clock is coming 25Mhz on CRO).

Let me know If I can use RGMII as RMII with GMII_SEL register.

Regards,
Krishna

0 Biser Gatchev-XID over 9 years ago in reply to Krishna Prasad

TI__Guru**** 393215 points

RMII requires 50MHz clock and has very tight timing requirements. You may be able to use this as GMII. See section 15.2.5 in the AM437X TRM Rev. D for necessary connections. I am stressing on the "may be able" part, because I'm not sure how this fast parallel interface will function over jumper wires on the board.

Processors

Processors forum

Using PRUSS port as RGMII port in AM4377 IDK board