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AM1808 USB2.0 eye diagram test with HUB?

Jun Dong
Prodigy 100 points
Other Parts Discussed in Thread: AM1808

first question is: How to config the AM1808 usb2.0 into a test mode and do a eye diagram test ? Is there some example software code?

second question is : How to config the AM1808 usb2.0 into a test mode with a usb hub and do a eye diagram test for  hub dowmstream? Is there some example software code?

  • 0
    TI__Guru**** 177846 points

    Jun Dong

    For the first question, have you get a chance to take a look at this document: http://www.ti.com/lit/an/sprab50/sprab50.pdf?

    For the second question, it is the job of the hub to send the test packet on its own, not AM1808.

    Thanks

    David

  • 0 in reply to David (ASIC) Liu
    Prodigy 100 points

    In SPRAB50 : the method used here is for the C6748/46/42 and omap-L1x8 to enumerate a known good device(a HS use falsh drive); at the end of enumeration, you will force the device to go into TEST_PACKET test mode via the code composer studio wath window.

    is there some more ditails about this method?

  • 0 in reply to Jun Dong
    TI__Guru**** 177846 points

    Jun Dong

    To execute the Test_Packet test, the software should first write the standard test packet (shown below) to the Endpoint 0 FIFO and set the InPktRdy bit. It should then write 8’h08 to the TestMode register to enter Test_Packet test mode.

    The 53 byte test packet to load is as follows (all bytes in hex). The test packet only has to be loaded once.

    00 00 00 00 00 00 00 00

    00 AA AA AA AA AA AA AA

    AA EE EE EE EE EE EE EE

    EE FE FF FF FF FF FF FF

    FF FF FF FF FF 7F BF DF

    EF F7 FB FD FC 7E BF DF

    EF F7 FB FD 7E

    Thanks

    David