TUSB8041: Device USB enumeration failed after plugging and unplugging host

HI Skyler:

    What are those devices connected to Hub2, can you send schematic of Hub 2 and 4 devices attached ?

   And how often the device not enumerating fail.

Regards

Brian 

Hi Brian

Devices is a Qualcomm QCS8550 board.

schematic of Hub 2 and 4 devices sent by email.

The probability of NG is 3%.

Add a case for today's attempt.

Case 4:

The power supply of devices1~4 consists of 5V(USB VBUS) and 12V(MAIN POWER),and they always on.

Use USB_VBUS to Contrl the 5V of devices1~4.

when HOST is plugged,USB_VBUS is high,5V of devices1~4 is on.

when HOST is unplugged,USB_VBUS is low,5V of devices1~4 is off.

The situation of device enumeration failure still exists.

Hi Skyler:

     Attached is schematic review for hub2 .

GTK_tusb8041_schematic _review.pptx

Regards

Brian

HI Brain：

Hi Skyler:

     AC value looks good.

     for item 3: USB_VBus (pin48) of hub 2 can control PWRCTLx if power switching is enabled. This will control the downstream port Vbus everytime connected to host.

     For TUSB542 EQ and DE setting, how did you get these settings? 

Regards

brian

Hi brian：

1. USB_VBUS of Device has other functions，so it cannot be connected to the PWRCTL of HUB2.

    In Case 4,we have tried using USB_ VBUS to Contrl the 5V(USB_VBUS of Device).From the results, these two methods should be the same,when USB_VBUS of HUB2 is high,5V(USB_VBUS of Devices) turns high,when USB_VBUS of HUB2 is low,5V(USB_VBUS of Devices) turns low. In this case,the situation of device enumeration failure still exists.

2. Settings of EQ and DE were estimated，we plan to adjust their values based on the actual situation.We have sent you the PCB signal length and PCB loss of this system,Do you have any recommended settings of EQ and DE.

Thanks and Best Regards.

Hi Skyler:

    For USB_Vbus , what I mean  is that USB_vbus can control PWRCTL inside the hub device. If USB_Vbus is off, PWRCTL can not be turn on.

    Regarding EQ and DE

Regards

Brian

Hi Brian

Follow your advice，we redone the trial，the situation of device enumeration failure still exists.

detarls please check my email.

Hi Brian

We have found your suggested settings for 542-host is CONF_A2-float,CONF_B2-float.

But using this setting will make the OS become 1.1v,our other OS is set to 0.9V.

Would it be better to set CONF_A2 to float and CONF_B2 to High？

Hi Skyler:

    You can set CONF_A2 to float and CONF_B2 to High to keep OS in 0.9v.

Regards

brian

Hi Skyler:

   So which is correct for main board? TU*Sb1002A or TUSB522p?

Regards

Brian

Hi Skyler:

    Here is EQ/DE setting for TUSB522p. I need schematic for main board to determine it's EQ1 or EQ2

Regards

Brian

Hi Brian

TUSB522p is correct.please refer to the email dated 2024.01.29.

Hu Skyler:

   Here is EQ/DE setting for TUDB522p.

  Main  issue could be downstream port vbus was not controlled by PWRCTL and PWRCTL can be affected by USB_VBUS pin

Regards

Brian

Hi Brian

We tested the situation of repeated power on and off of Devices1~4.

HUB on Mid Board and HUB on Main Board2 are always on.

When Devices1~4 is power off,DC_12V and USB_VBUS(5V of devices) Pulled low.

When Devices1~4 is power on,DC_12V and USB_VBUS(5V of devices) Pulled high.

The situation of device enumeration failure still exists, the failure of USB enumeration seems to be related to USB_ VBUS has no direct relationship.

Thanks and Best Regards.

Hi Skyler:

   Did it always fail on same port or different port?

Regards

Brian

Hi Brian

The failed prots are random.

Almost all prots have failed, and the number of failures is average.

Thanks and Best Regards.

Hi Brian

About test pin.

In our schematic, it's float,but in your reply on January 24th,test pin should be grounded.

in Datasheet,test pin is an internal pulldown.Will it have any impact if it's float?

Thanks and Best Regards.

Hi Skyler:

      Since there is internal pulldown , it should be ok if test pin is floating. 

      For the 4 devices, did you connect USB2 signal as well?

Regards

Brian

Hi Brian

The USB 2.0 signal is connected.

And when USB enumeration fails, the devices are not enumerated as a USB 2.0 device.

Thanks and Best Regards.

Hi Skyler:

   When it fails, both USB3 and USB2 failed for that same port? are there power on sequence requirement for device 1 to 4?

Regards

Brian

Hi Brian

Both USB 2.0 and USB 3.0 signals are connected.

Under normal circumstances,the devices will enumerated as a USB 3.0 device.

When the enumeration fails,NG device have not been enumerated as a USB 3.0 devices,also failed to enumerated as a USB 2.0 device due to USB 3.0 communication failures.

Equipment has requirements for power on sequence,when the device is powered on, it needs to be powered on 12V before 5V.

When NG occurs,no abnormalities were found in the power on sequence of the device,and the device is in a normal startup state.

Hi Skyler:

    Can we get the user manual for that device?

Regards

Brian

Hi Brian

The wire length of USB3.0 on the Main Board1 and MID Board have changed.Can you help us check if the settings for TUSB522 can still be used？

The updated file has been sent to your email.

Thanks and Best Regards.

HI Skyler:

  I saw trace length changes on main board 1, what changes made  on Mid board?

Regards

Brian

ticket closed due to project stopped.

Regards

Brian