XMC4700 RMII Issues

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User21284
Level 1
Level 1
I have a board with an XMC4700 connected to a KSZ9567R via RMII. The RMII link is working on most boards & on the ones where it is failing replacing the XMC4700 fixes the failures. Also, on some of the boards that are failing, letting them run for 10's of minutes allows them to start working which makes me think the issue goes away with heat. We are also wondering if replacing the XMC4700 is simply heating up the board & allowing it to work although warming up a failing board doesn't seem to get it to work.

Any thoughts or input would be appricated.
Steve
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2 Replies
SudheeshK
Moderator
Moderator
Moderator
250 sign-ins First question asked 750 replies posted
Hello,

We would like to know more details about this issue.

1. Did you try swapping the XMC4700 devices between a failing and a passing board? After swapping, did the failing board started working? Please let us know the results.
2. Please let us know the total number of XMC4700 devices that you tested and the number of devices that failed.

Thanks and Regards,
Sudheesh
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User21284
Level 1
Level 1
Thanks Sudheesh,
1. Swapping the XMC4700 on failing boards fixes the issue.
2. In round numbers, we have built 1000 boards and around 200 have failed.

Also, some of the boards that fail start working after they have been running for several mins. If I cool the XMC4700 micro with freeze spray, the RMII communications fail. Letting the micro warm back up allows the RMII comm to start working again.

Steve
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