TUSB8043A: How to program TUSB8043A EEPROM to change the manufacturer description string

Manoj G

Part Number: TUSB8043A

We are using the TUSB8043A in our control board and the board also has the PIC18F47j53 in the design (it does not have external EEPROM). The issue we are facing is putting the unique serial number for each of these boards.

So I wanted to know how do we program the the manufacturer string in the TUSB8043A chip so that when the control board USB is inserted to the PC we can get the unique serial number from the USB information.

11 months ago

0 Clemens Ladisch 11 months ago

Guru 256550 points

If you do not have an EEPROM, the PIC must use the SMBus Slave mode to change the registers before the hub connects to the upstream port. See sections 8.4 and 8.5 of the datasheet.

0 Manoj G 11 months ago in reply to Clemens Ladisch

Prodigy 10 points

Hi Clemens, Thanks of the reply. So we set the SMBUSz/SS_SUSPEND pin to ground to go into SMBus mode? And after we go to this mode is there some GUI software that we use to program the eeprom?

0 Brian Zhou 11 months ago in reply to Manoj G

TI__Guru** 111520 points

If you use SMBus , then no EEPROM is needed.

Best

Brian

0 Manoj G 11 months ago in reply to Brian Zhou

Prodigy 10 points

Thank you. How do we put the USB Hub chip to SMBus mode so that I could configure the hardware description string that would be persistent across power cycle?

0 Clemens Ladisch 11 months ago in reply to Manoj G

Guru 256550 points

In SMBus mode, the change is not persistent. The PIC must reprogram the registers after every power on.

If you want permanent changes, you must use an EEPROM.

0 Manoj G 11 months ago in reply to Clemens Ladisch

Prodigy 10 points

Got you. So our main objective is to save the serial number so that it persist across reboot and we could read that serial number somehow.

Can we use OTP ROM to save that of information?

0 Clemens Ladisch 11 months ago in reply to Manoj G

Guru 256550 points

The OTP ROM cannot store the serial number string. You'd have to store it in the PIC's flash.

0 Manoj G 11 months ago in reply to Clemens Ladisch

Prodigy 10 points

Hi Clemens, Thank you. We wanted to make the serial number configurable without having to go through updating the firmware code to update the serial number, compiling the firmware and flashing the PIC for new firmware.

Is it possible to write that serial number to the PIC's flash at runtime that would be persistent? We are using PIC18F47j53

+1 Clemens Ladisch 11 months ago in reply to Manoj G

Guru 256550 points

Yes, the PIC18F47J53 can write to its flash. You have to ensure that you do not erase/write over any already-used memory locations.

0 Manoj G 11 months ago in reply to Clemens Ladisch

Prodigy 10 points

Thank you for all the responses. I will be using this technique to write serial number for now. May be will add EEPROM in the next board re-spin.

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TUSB8043A: How to program TUSB8043A EEPROM to change the manufacturer description string