TUSB8043A: About EEPROM writing via USB hub and I2C mode

Shuji Ishiwata said:

1) I have a question about writing to the EEPROM via a USB hub.
As stated on page 17, section 8.3.3 of the datasheet,
Is my understanding correct that:
 - Programmable via the USB hub's Upstream port
 - Programmable via the USB hub's Downstream port
Is my understanding correct?

you can program EEPROM  via HUB's upstream port

Shuji Ishiwata said:

I have a question about reading the EEPROM when powering on in I2C mode.
As stated on page 22, section 8.4.2 of the datasheet, if the EEPROM has not been written to, the data at address 00h is not 55h, so is it correct to assume that it will start with the default settings?

with empty EEPROM installed , after power on, hub will stuck in programming mode.

so you either install programmed EEPROM, or don't install empty EEPROM.

Best

Brian

Hi Brian,

I really appreciate your answer.

I'm sorry, I misunderstood the question.
Is my understanding below correct?

- Programmable via the upstream port of the USB hub
- Not programmable via the downstream port of the USB hub

I have another question regarding the operation of I2C mode.

Is my understanding correct that I should choose one of the following two patterns?
① Install a pre-programmed EEPROM (mounted on the board)
→ The hub will operate with the settings stored in the EEPROM.
The settings set by hardware strapping will be invalid (EEPROM settings take precedence)

② Do not install an empty EEPROM (not mounted on the board)
→ The hub will operate with default settings.
The settings set by hardware strapping will be valid

In case ②, the hub will remain in programming mode. Is this acceptable?

Best Regards,
Ishiwata