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TUSB2046I: Resolution for TUSB2046I with TPS2044D?

Part Number: TUSB2046I
Other Parts Discussed in Thread: TPS2075, , TUSB2046B, TUSB2036

Was there a resolution for TUSB2046I with TPS2044D? I saw some chip swap to TPS2075?

We see devices enumerate properly, except HID. That may be a speed issue or a power management issue. Seems like the slow stuff doesn't work.

  • Hi Mark,

    We don't have a known issue with TUSB2046B and TPS2044D.  What kind of issue are you seeing?  Do low speed devices like mice work?  Do the HID devices enumerate?  

    Regars,

    JMMN

  • Hi JMMN,

    We are seeing on Linux,
    for dmesg

    `````
    new low-speed USB device number 3 using dwc2
    attempt power cycle
    `````

    It appears to be recorded well here: https://www.raspberrypi.org/forums/viewtopic.php?t=246248

    I see a response from TI here

    https://e2e.ti.com/support/interface-group/interface/f/interface-forum/595619/tusb2046b-single-or-multi-transaction-translator

    "Neither, the TUSB2046B is a full speed hub so it has no transaction translators. The TUSB4041 or TUSB4020B are high speed USB hubs with multi TT support, either of those would probably be a better fit for the application."

    I just wanted to see if there's a work around or is it a lost hope?

    I can enumerate a keyboard mouse over a wireless dongle, so I think it's the full speed / high speed issue..

    Thanks! Mark

  • Hi Mark,

    Are you connecting the wireless dongle to the TUSB2036 or directly to the raspberry pi?

    Reading through the raspberry pi forum /notes it looks like there is an issue supporting FS hubs with multiple devices connected .  It is a little difficult to tell what the problem is but since the raspberry pi has an issue both with too many FS/LS devices connected to a Single TT hub and reports issues with FS/LS devices behind USB 3.0 hubs which typically have MultiTT USB 2.0 hubs incorporated, it may be a bandwidth allocation issue.  

    Transaction translators only are used in HS hubs (480 Mbps) to translate between the upstream HS port and downstream FS/LS devices.  The TUSB2036/2046/2077 family are all 12 Mbps hubs.  For the FS hubs, the raspberry pi would have to connect at full speed to the hub and it looks like this may be an issue, based on this statement:

    Old webcams may be full speed devices. Because these devices transfer a lot of data and incur additional software overhead, reliable operation is not guaranteed.

    If you can share the DP/DM behavior on the downstream port that isn't connecting, I can help confirm this isn't a signal quality issue but this looks specific to the raspberry pi setup.

    Regards,

    JMMN