TUSB8020B: Interface forum

W. Hernler

Part Number: TUSB8020B

Tool/software:

We built our own PCB with TUSB8020B without EEPROM and without SMBus interface. Unlike the EVAL-Board our solution does not attach the upstream port to the PC until the cfgActive Flag is set via SMB. How is the TUSB8020B in the EVAL-Board configured so that it immediately attach after power on?

4 days ago

0 Brian Zhou 3 days ago

TI__Guru*** 146195 points

Hi Hernler:

Even if no EERPOM needed, hub should be in I2C mode (SMBUS=H), other wise, upstream port will not be connected until the cfgActive Flag is set via SMBUS.

Best

Brian

0 W. Hernler 1 day ago

Prodigy 20 points

Thank you for the answer but I need to know how this is be done in the TUSB8020BEVM. With this eval-board the upstream port is connected as soon as the power supply is switched on. I removed the EEPROM and there is also no SMBUS communication and it still connects. What is the secret behind it? Does it has a programmed OTP?

0 Brian Zhou 20 hours ago in reply to W. Hernler

TI__Guru*** 146195 points

on EVM, hub is configured in I2C mode. If there is EEPROM is detected, hub will read EEPROM information, if EEPROM is not detected, hub will load default configuration . Hub can work in default configuration without EEPROM.

Best

brian