AM3358 RGMII Series Termination

Nabeel Khan

Other Parts Discussed in Thread: AM3358

Hey Team,

According to the following Schematic Checklist: http://processors.wiki.ti.com/index.php/AM335x_Schematic_Checklist There are no series terminations required for MII signals.

Are series terminations required for RGMII lines?

If so, what values are required?

Note that a Marvell PhY is being used.

Regards,

Nabeel

over 11 years ago

0 Biser Gatchev-XID over 11 years ago

TI__Guru**** 393215 points

Hi Nabeel,

Please check what are the Marvell requirements.

0 Nabeel Khan over 11 years ago in reply to Biser Gatchev-XID

TI__Intellectual 1455 points

The Phy is a Marvel 88E1512, however we do not have documentation since Marvell requires an NDA for access.

On the AM3358 Starter Kit, there are 22 ohm terminations on the transmit and recieve sides. I can't seem to find any notes on why these values are chosen.

Any ideas where to find guidelines on RGMII implementation for AM3358?

Regards,
Nabeel

0 -DK- over 11 years ago in reply to Nabeel Khan

TI__Mastermind 27890 points

Nabeel,
These resistors are not *required* from the TI-side, but it can be a good idea to have zero-Ohm options present on the board in case excessive reflections are seen. If implemented, they should be placed close to the TX pins to be most effective.

I cannot comment on the Marvell requirements...the customer really should have access to their docs if they plan on implementing their device...

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AM3358 RGMII Series Termination