About i.MX53 ENGcm11151.

[satoshishimoda]

Hi community,

Our partner have some question about i.MX53 errata ENGcm11151.

Please see their questions as below.

[Q1]

Would you let us know more detail of projected impact "False tranfer of USB"?

What timing, and what transfer will be false?

(e.g. Cannot get USB device descriptor when USB device is attached.)

[Q2]

They want to reproduce this errata to confirm that this errata is not occurred when USB is configured correctly certainly.

Is there any way to reproduce this errata?

According to the erratasheet, this errata will be happen when USB is not configured correctly, but I feel not only this errata but also other errors are occurred when USB is not configured correctly.

Best Regards,

Satoshi Shimoda

[CarlosCasillas · Accepted solution]

Hi Satoshi,

According with the experts, this errata is about accessing invalid memory. i.e. hresp will assert when there is an error accessing the memory.

This will only happen when the controller tries to access a memory location that is not accessible. I.e. when the transfer descriptor contains invalid pointers.

When that happens, the controller will send the data that it found on the internal bus instead of aborting the transfer.

This problem will never occur in properly designed a system as there will not be false pointers.

Hope this will be useful for you.
Best regards!
/Carlos

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