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Is there a way to enable the High Speed USB 2.0 subsystem in the DM37x to generate a fixed Start of Frame (SOF) pattern allowing me to do eye pattern testing?

paul herbert
Prodigy 55 points
Other Parts Discussed in Thread: DM3730

I'd like to test the signal integrity of my host card employing the DM3730 DaVinci Processor.  Since the USB 2.0 Silicon in the DM3730 is USB2.0 compliant there must be a way of enabling it through a bit in a test register.

  • 0
    TI__Guru 65405 points
    Hi Paul,
    You can check the Start of Frame (SOF) by reading the HCINTERRUPTSTATUS[2] SF bit. You can find more details in the DM37xx TRM Table 22-170. HCINTERRUPTSTATUS.

    BR
    Tsvetolin Shulev
  • 0 in reply to Cvetolin Shulev-XID
    Prodigy 55 points
    Tsvetolin,
    Yes that will tell when the 1 millisecond based Full Speed SOF has occurred but I'd be more interested in the 125 uSec (8 micro-frame) interrupt since I'd like to look at the integrity in the pattern in High Speed mode.

    I did find a bit in the PORTSC_i register called the Port Test Control. It has a value identified as "Test Packet" that seems to match a section in the USB 2.0 (section 7.1.20) labeled "Test Mode Support" specifically Test Mode "Test Packet". I'm going to disable the periodic and asynchronous schedule, clear the RunStop (all in the USBCMD register) and then write the PORTSC_i with the "Test Packet" value in the PTC field and see what happens.

    Wish me luck.