TMS320C6A816x: Errata with Advisory 1.1.18 CPGMAC 1-Gbps Mode Does Not Work When EMAC_TXCLK is Not Running.

Mihir Shah

We have used TMS320C6A816x EMCA0 as GMII and EMAC1 as MII port. Among these EMAC0 GMII PHY doesn’t provide TXCLK.

The errata says that 1Gbps mode will not work in case of TXCLK is not available.

Question: Is this applicable only in case of Ethernet boot? Or TXCLK has to be driven all the time to make 1Gbps work.

(We are booting system from NAND Flash)

Thx,

Mihir Shah

over 12 years ago

0 MarcPyne over 12 years ago

TI__Mastermind 25055 points

Hello,

The errata applies to Ethernet boot.

Regards,
Marc

0 Anshuman Saxena over 12 years ago in reply to MarcPyne

TI__Mastermind 19985 points

Hi,

The TXCLK is needed only when the EMAC controller is being enabled. So, if the PHY that is being used has option of providing TXCLK even in the gigabit mode, then there is no problem EMAC controller to come up.

If your PHY does not have the option of driving TXCLK in gigabit mode, then before enabling EMAC controller, please disable auto-negotiation on the PHY and forcibly put it in MII mode. Once this is done, the EMAC controller can be enabled. After this, you can put the PHY in auto-negotiate mode again using MDIO commands.

Regards,

Anshuman

PS: Please mark this post as verified, if you think it has answered your question. Thanks.

0 Mihir Shah over 12 years ago in reply to Anshuman Saxena

Prodigy 150 points

Hi Anshuman,

You mean the GMII interface PHY (KSZ9021GN) which I have used on EMAC[0] is to be in MII without auto-negotiation by default. And once EMAC controller is initialized, I can configure it back to with auto-negotiation.

We assume that as the PHY goes in Auto-negotiation, it will jump to GMII based on link.

Is that correct?

Mihir

0 Anshuman Saxena over 12 years ago in reply to Mihir Shah

TI__Mastermind 19985 points

Hi Mihir,

Yes, your statement is correct.

Regards,

Anshuman

PS: Please mark this post as verified, if you think it has answered your question. Thanks.

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TMS320C6A816x: Errata with Advisory 1.1.18 CPGMAC 1-Gbps Mode Does Not Work When EMAC_TXCLK is Not Running.