• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Subscribers 31 subscribers
  • Views 263 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Original question:

TUSB8020B - OPT and EEPROM programming

TUSB8020B-Q1: Hub configuration

Yen Nee Lee
Prodigy 110 points
Part Number: TUSB8020B-Q1

Hi,

If the hub downstream is connected to:

- Port 1 to non-removable USB device

- Port 2 is connected to USBA connector - removable USB device that requires VBUS to power up the device

1. Do i need to change any hub configuration? 

2. Can the host change the hub configuration via the upstream USB connection? We do not have I2C or SMBUS interface connected.

3. How does the OTP ROM works? If i need to use OTP ROM, what is the pull resistor value required on SCL/SMBCLK and SDA/SMBDAT? Can these pins remain permanently pull up?

Thanks

  • 0
    TI__Guru 60865 points

    Hello,

    1. To be compliant to the USB specification, a non-removable port should be marked as non-removable using the register settings of the hub, but functionally this is not required.  Setting the non-removable bit only changes what the hub reports in its descriptors, not its actual operation.

    2. The configuration can be set in the OTP only if no SMBUS or I2C is available.

    3. Yes, SDA and SCL can be pulled up externally as long as SMBUSz is high.

    Let me know if the customer wants to set the registers via OTP or not and I can provide the tool.

    Regards,

    JMMN

  • 0 in reply to JMMN
    Prodigy 110 points

    Hi,

    To confirm, to support OTP function, once i have a pull up at the SCL and SDA pins, the configuration will be done via the upstream USB communication?

    May i know if a 4.7kOhm pull up resistor on SDA and SCL pins ok? 

    We are still not sure if OTP reconfiguration is needed. Can you provide your email address so that we can contact you for the tool when needed?

  • +1 in reply to Yen Nee Lee
    TI__Guru 60865 points

    Yes, those pullups on SDA/SCL are fine for OTP programming.

    Please accept my friend request and I can share the tool there.

    Regards,

    JMMN