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TUSB8020B: Programming tool for the HUB

Part Number: TUSB8020B

I am looking for the programming tool for the TUSB8020B.

I would like to set the port removable configuration for downstream ports 1 and 2.

I assume this is a windows based tool, which I can run on an upstream connected PC.

Do the SCL/SDA pins need to be pulled up to program OTP (as per the datasheet)? No external interface is used on our product (no EEPROM, etc.), and so these pins are not connected to anything currently. Could potentially add TP's for programming this in a test jig if required.

Thanks,

Chris

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  • Hi Chris,

    Please accept my friend request and I will send you the tool. Send me a note when you accept my request so I see it has been accepted.

    Yes, pullups are required on SDA/SCL even for OTP mode. The device doesn't enter programming mode unless these pins are pulled high.

    Regards,
    JMMN
  • JMMN,

    Thank you for the tool. I am still having issues though, and wondering what I am missing. When I run the tool on the upstream connected PC (via USB3 A-B cable), it says no 8040 device found.

    I do not have any external memory (EEPROM), as I only want to change port removable configuration (OTP).

    We do not have TPs (currently) for I2C pins (pins 2,3), or SMBUSz (pin 22)... so I have manually soldered 3.6K pull-ups to 3.3V for each of those.

    I added the pull-up on SMBUSz, due to your response in a related case, where you said:

    The hub will stay in programming mode under the following conditions:
    1. (SMBUS mode) SMBUSz asserted and the SMBUS host has not set/cleared the cfg active bit in the hub registers.
    2. (I2C mode) SMBUSz not asserted, SDA and SCL pulled high and a blank EEPROM attached.
    The hub does not automatically leave programming mode after a set amount of time.

    I was not sure if SMBUSz needed a pull-up, as the datasheet indicates it has an internal one. External did not help though.

    Please let me know what I need to do to get this into programming mode.

    Thanks,

    Chris
  • Hi Chris,

    You don't need an external pullup on SMBUSz, the internal is fine. I'm sending you instructions on how to force load the driver.

    Regards,
    JMMN
  • To summarize (for anyone interested), as I have had some communications with JMMN in private:

    In order to program the TUSB8020B OTP, you need a tool which TI can provide if you request it. This is their eFuse programming tool. They also have a different tool for programming external EEPROM.

    I have tried programming OTP on two different units. One had pull-ups on SDA / SCL (the datasheet at the time of writing this says this is required):

    The second board had no pull-ups, but was detected and programmed just fine. This is interesting, as the datasheet also indicates these lines are pulled down internally.

    I have requested JMMN check with the factory / engineers to determine if this is a mistake in the datasheet - and I am awaiting his response (after which I will resolve this case).

    Thanks,

    Chris

  • Hi Chris,

    Design confirmed that external pullups are not needed for OTP programming.

    Regards,
    JMMN