DP83867CR: DP83867

Balaji Padmanaban

Part Number: DP83867CR

I have a similar kind of issue.

I have RGMII to mac.

I drop packets on 2 boards when i increase the ping size to 64000 bytes and issue happens as low as 640 bytes(10% packet loss)

Did you figure the issue buddy?

over 5 years ago

0 Nikhil Menon over 5 years ago

TI__Genius 11725 points

Hi Balaji

DP83867 has delays enabled on RGMII TX and RX by default. Do you have any delays implemented in your MAC?

Thank you,

Nikhil

0 Balaji Padmanaban over 5 years ago in reply to Nikhil Menon

Intellectual 705 points

HI,

Am doing a timing analysis and a scope capture to verify that.

And just curious how would 1500 bytes or 64 bytes cause the the link to drop packets.

The bits are parallel anyway and setup time and hold remains the same for n bytes.

Is that correct?

why do you suspect RGMII delays?

0 Nikhil Menon over 5 years ago in reply to Balaji Padmanaban

TI__Genius 11725 points

Hi Balaji,

To clarify are you running into packet loss regardless of packet size? Mismatch in RGMII delays can cause this issue. Also be sure that the clock matches the specification in Section 9 of the datasheet. Refer to the app note linked for additional info. http://www.ti.com/lit/an/snla290/snla290.pdf

Thank you,

Nikhil

0 Nikhil Menon over 5 years ago in reply to Nikhil Menon

TI__Genius 11725 points

Hi Balaji,

I'm going to close this thread. If you need any further assistance, please open a new thread.

Thank you,

Nikhil

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DP83867CR: DP83867