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AM3352: USB test

zhengguang yang
Expert 1390 points

Part Number: AM3352

Hi

We are using am335x to develop a customized board.

Refer to http://processors.wiki.ti.com/index.php/UsbgeneralpageLinuxCore#musb_driver_debugfs. Use the following command:

echo "test packet" > /sys/kernel/debug/musb-hdrc.0/testmode

The waveform is as follows:

The waveform is not continuous, and the pattern is sent every 500 milliseconds.

When no pattern is output, the corresponding waveform is as follows:

So I'd like to ask if there is something wrong with our test method.

Our SDK version is 05.03.00.07

  • 0
    TI__Mastermind 27890 points

    Hello,

    This looks correct. If you are expecting to see the USB timing eye itself, the scope will need to have the USB2.0 Compliance Package installed. Alternatively, some scopes can output .TSV or .CSV files that can be input into the USB-IF USBET20 Electrical Analysis tool. It is located here:

  • 0 in reply to -DK-
    Expert 1390 points

    Hi DK:

    The following waveform is another customized board of AM3352，SDK version is 06.00.00.00:

    But the waveform of our new board is as follows, SDK version is 05.03.00.07:

    The waveform will output for a while and then disappear.　But the waveforms on the old boards seem to never  disappear.

  • 0 in reply to zhengguang yang
    TI__Mastermind 27890 points

    Hmmm...these last scope plots do look odd.

    1) Does the interface function normally when not in Compliance mode?

    2) Can you try your new boards with SDK 6 to ensure that this is not an OS artifact?