AM335X USB Communication Error

xing lui

Other Parts Discussed in Thread: AM3352

Hi,

We found many errors in usb communication.toggle error,crc error and so on.It looks like as the usb controller issue.Can you give any suggestions?

we use the AM3352's USB1 as host mode.

This bulk out is from AM335X to other usb device.

over 9 years ago

0 Biser Gatchev-XID over 9 years ago

TI__Guru**** 393215 points

Hi,

Which Linux SDK are you using?

0 xing lui over 9 years ago in reply to Biser Gatchev-XID

Intellectual 990 points

Hi Biser,
We are using WinCE platform.Hiwever,I think this issue has nothing to do with software.the usb controller will handle the data toggle .

0 xing lui over 9 years ago in reply to Biser Gatchev-XID

Intellectual 990 points

Hi,

We and our customer have catch mang usb packet errors by usb analyzer.for examples,CRC errors, toggle error.However,It became much fewer when we change the host as usb 1.1 mode(full speed).We can't explain why this issue occurs to our customers.

0 xing lui over 9 years ago in reply to xing lui

Intellectual 990 points

The max usb packet size is 512 bytes.I don't know why the usb host output 516 bytes packet

0 xing lui over 9 years ago in reply to xing lui

Intellectual 990 points

We alse set the fifo size is also 512 bytes

0 Biser Gatchev-XID over 9 years ago in reply to xing lui

TI__Guru**** 393215 points

WinCE is not supported by TI, AM335X BSPs for WinCE are developed and supported by 3-rd party Adeneo Embedded. From hardware perspective there are no errata in the AM335X silicon that can produce this behavior. I will ask the USB experts if they can at least point you to possible causes for this.

0 -DK- over 9 years ago

TI__Mastermind 27890 points

This could be a result of poor signal integrity. Please verify that the recommended layout guidelines (SPRAAR7) were followed for this design.

0 xing lui over 9 years ago in reply to -DK-

Intellectual 990 points

Hi,

Does the poor signal also result in the data toggled error?

0 Bin Liu over 9 years ago in reply to xing lui

TI__Guru**** 168761 points

Do you have CPPI DMA enabled? If so, please try to disable it to see the data toggle problem still happens.

0 xing lui over 9 years ago in reply to Bin Liu

Intellectual 990 points

no,I disable the DMA function.If I enable it,it will generate more other issues.

0 -DK- over 9 years ago in reply to xing lui

TI__Mastermind 27890 points

xing lui said:
Hi,
Does the poor signal also result in the data toggled error?

It most certainly could. Only 2 bits seperate a DATA0 from a DATA1 PID, and the fact that you see significantly fewer errors in FullSpeed mode is also a strong indicator that the design suffers from poor signal integrity. This can be verified by performing USB-IF electrical testing on your design.

0 xing lui over 9 years ago in reply to -DK-

Intellectual 990 points

Hi,
We do eye diagram test and it passed in high speed.We doubt that MUSBMHDRC is not ready to send packet when the TXCSR.TxPktRdy is set.And the errors offen occurs in these packets of 512 bytes.We guess the MUSBMHDRC try to send packet directly after setting the TxPktRdy bit. so we want to knodirectw when the MUSBMHDRC is ready after loading a data packet into the FIFO.

0 xing lui over 9 years ago in reply to -DK-

Intellectual 990 points

Hi,
It's very helpful If anybody can give us some suggestion to find why this controller will transmit 516 bytes packet when driver only write 512 bytes to FIFO(It transmits OK with 512 bytes at the third time )

0 xing lui over 9 years ago in reply to -DK-

Intellectual 990 points

Hi,
we found that if we write data as all 0x47 to the FIFO,the crc error/toggle error occurs much more frequently.could you give any suggestions?

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AM335X USB Communication Error