DCA1000EVM: Gigabit Ethernet interface requirement.

Edd Inglis

Part Number: DCA1000EVM

I have spent some time empirically discovering that the DCA1000EVM's Ethernet interface only works when connected at 1 Gbps. That is, when connected to a 100 Mbps Ethernet port, it will not even respond to ARP messages.

I found this question: "DCA1000EVM: mmwave Studio : FPGA version not read, Ethernet Cable Not Connected, ADC Data Capture not working" which mentions in passing that a GigE adapter is required "as DCA1000 EVM supports up to 600 Mbps" but its top speed should not affect its ability to communicate slower.

Can you confirm this is a true requirement and, if so, point me (and future folk) at the relevant documentation? If it's not a true requirement, can you suggest what I might be doing wrong otherwise?

It's certainly the first time I've encountered a device that behaves this way.

over 5 years ago

0 Ishita Kochar over 5 years ago

TI__Mastermind 31680 points

Hello,

Yes, it is correct The DCA1000EVM supports a Gigabit Ethernet port to provide the connection to the network. You can refer to the DCA1000 user guide to know more about this requirement.

Regards,

Ishita

0 Edd Inglis over 5 years ago in reply to Ishita Kochar

Prodigy 70 points

I searched the doc, and discovered that it does indeed say:

"1-Gbps Ethernet port" under the "HOST PC configuration" section of "3.1 Prerequisites".

( Does anyone honestly ever read those sections? They're always either out-of-date or wildly-overspec'd. But I digress... )

It is still very unusual in my opinion for a Gbps Ethernet device to fail to function at all at 100 Mbps or less. I believe it would be useful to make this much more explicit in the documentation.

0 Ishita Kochar over 5 years ago in reply to Edd Inglis

TI__Mastermind 31680 points

Hello,

The reason for this limitation was because the FPGA does not have a processor core to implement all the Ethernet mac features. So it was hard coded to operate in 1Gbps mode.

Thanks for the feedback, we will definitely incorporate this in the updated documentation to help users like you :)

For now, I have updated our FAQ page based on your input.

Regards,

Ishita

0 Edd Inglis over 5 years ago in reply to Ishita Kochar

Prodigy 70 points

Excellent. Thanks for the explanation.

Edd.

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DCA1000EVM: Gigabit Ethernet interface requirement.