TUSB4041I: Port Used Configuration Register

Hi Brian

When I disabled the port, the host gave no response for the attached USB device.
After that, I enabled the port again. However, the host still can't detect the attached USB device, even after unplugging and reattaching it.
I've set 1 to 0x8 (Port used configuration) to enable the specific port.
Do you mean this operation is enough to make the disabled port work again?

Thank you,

Shin.

Did  you clear cfgActive bit  in register xF8?

Best

Brian

Yes, I've tried clearing 0xF8 and setting it to 1.
There is no effect.
In the data, it says writing 0 has no effect.
I can disable the USB port after activation.
But, I can't enable it after it's been disabled.

Thank you,

Shin.

Did you set used ports (8h) to enable it?

Best

Brian

Yes,I did it. 

Setting 0x8 to 0xE to disable PORT 1.

After that, PORT 1 is not working.

And next, setting 0x8 to 0xF to enabel PORT 1, but PORT 1 is still not working

And setting 0xF8 to 0x1 had no effect.

If you know the full procedure for enabling the specific USB port, could you let me know?

Thank you,

Shin

Let me try on our EVM before Wed.

Best

Brian

Hi Brian, 

Do you have any progress? If so, please let me know any data you might have.

Thank you,
Shin.

Hi Brian,

According to your mention, USB port 1 should function correctly after the following operations.
write 0xe to 0x8 // disable USB port 1
wirte 0x2 to 0xf8 // reset SMBUS
write 0x1 to 0xf8 // activate device

In my case, USB port does not re-enabled once it has been disabled.

I've attempted the following operations to re-enable USB port 1
write 0xf to 0x8 // enable all USB ports
wirte 0x2 to 0xf8 // reset SMBUS
write 0x1 to 0xf8 // activate device

However, USB port 1 remains disabled.

I need a power reboot to operate USB port 1 it has been disabled once.

I believe triggering the GRSTz pin is necessary to enable USB port 1.
However, the GRSTz pin on our board is connected to ground through a capacitor.
Therefore, I cannot control the GRSTz pin.

If you can re-enable a disabled USB port using SMBUSRST and CFGACTIVE bits control,
what could be wrong with my test scenario?

Regards, 

Shin.

I tested TUSB8044A, maybe TUSB4041 is a little  different. I may need to order TUSb4041EVM to test.

Best

Brian

I found TUSb4041 EVM, will test on early next week.

Best

Brian

Hi Shin:

   You are right, TUSB4041 can not  recover all ports once some ports got disabled unless device got reset.

Regards

Brian

Hi Brian,

I was hoping for a positive response even though my expectations weren't high.
We've spent considerable time verifying this issue, particularly whether the disabled USB port was recoverable during runtime.
I believe TI should clearly describe this case in their datasheet to avoid similar issues in the future.

Anyway, thank you very much for your support.

Regards, 

Shin.