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TUSB8043: Help with getting started

Scott Williams69
Prodigy 40 points
Part Number: TUSB8043

Hi there,

I've just got back a completely assembled board for a custom design I am making. We are using the TUSB8043, with some downstream devices. Here is a snippet of the design:

As you can see, the upstream is just a PC. The downstream devices are a USB Flash Drive (UFD), a USB camera, and an on-board microcontroller which just acts as a virtual com port.

I believe the assembly and design went well, and the HUB is getting supplied a very stable and reliable 1.1V and 3.3V - so that's all good.

I thought maybe the device would work out of the box, with the resistor pullup/pulldown configurations I have made. However, upon trying some of the downstream ports, I can't seem to see any immediate results.

So my question: is there any configuration that is needed to get the USB Hub working? I have I2C access to the device, but from what I can tell the I2C registers are all just "Extra" settings and I can't see any hard-enable or anything that seems like it is critical. Likewise, I can't seem to see any of the external enable pins that are needed to be pulled correctly for the device to work (besides GRST#).

I would really appreciate any help on this. Thank you!

  • 0
    Prodigy 40 points
    Update: I have realised upon further reading the datasheet some steps, including:

    - Setting the DeviceRemovable register so I can enable ports, both as removeable/non-removeable but also in general
    - Setting the PortUsed register to enable ports appropriately

    After setting these bits (and getting an ACK from the chip) I still haven't had any luck, so I'm guessing there are further steps. Any help would be appreciated :)
  • 0 in reply to Scott Williams69
    Prodigy 40 points
    There is one final critical step:

    - The SMBus Status register. Upon initial glance, one would think this is just status of the device or the I2C bus. But no - there is a critical bit that needs setting on this register, to actually "put in place" and make the HUB start working.

    For those who need help getting the Hub up and running, these 3 steps I've listed are all you need - mine is working brilliantly on all 3 ports now!
  • 0 in reply to Scott Williams69
    TI__Guru 64326 points

    Hi Scott,

    Alternatively to enter I2C mode directly from power up (or when GRSTz is de-asserted), connect a 4.7-kΩ pullup resistor to VDD33 on SMBUSz,SS_SUSPEND pin or a leave unconnected to use the internal pull-up.