TUSB8042A: Not Seeing USB Ports on The Computer Side

Hi Furkan,

No register configuration is needed.  Can you confirm the size of the capacitor on GRSTz?  Does the downstream port power turn on?

There should be two hub instances in Device Manager, one for the superspeed hub and one for the USB 2.0 hub.  It sounds like only the USB 2.0 hub is loaded.

Is the hub connected directly to the host or does it connect through a cable?

Installing the pullup on the PWRCTL outputs will enable battery charging, please remove them if that is not required.

Regards,

JMMN

Hi JMMN,

First of all, thank you for your quick return. In response to the questions you have asked;

1- The capacitor we use has a value of 1uF, 10V.

2- The powers of the downstream ports are active.

3- The hub is first soldered directly to the connector on the PCB and connected to the computer with a cable from the connector output. (The connector and cable conform to USB 3.0 structure.)

I have some questions about the Hub. Why should I see 2 different Hubs for USB 3.0 and USB 2.0 in device manager when I plug the Hub into the computer ? (Currently I can only see 'Generic USB Hub' expression in device manager.)

In addition to these, are there any ideas you can suggest to solve the problem as soon as possible? I wish you good work.

Best Regards, 

Furkan

Hi Furkan,

The TUSB8042A works as a USB 3.0 hub and a USB 2.0 hub concurrently.  The buses are separate.  What OS are you using?  If it is Windows, can you install usbview.exe or USB Device Tree Viewer and send a screen capture?

Have you tried connecting a USB 2.0 only device or a keyboard or mouse to the USB ports to see if any of those work?

Regards,

JMMN

Hi JMMN,

In response to your questions;

1- I am using a Windows based operating system. Apart from that, the screenshot you want is attached. As seen in the attached picture, I can see all the ports I use actively on USBview.exe. Also, I still cannot see the TUSB8042A chip as a 'Super Speed Hub'. At first, I connected the PWRON4z_BATEN4 (Pin 32) and PWRON3z_BATEN3 (Pin 33) outputs of the downstream port in the schematic to GND in order to run the ports where I couldn't get any output before and I observed that the ports were working.

2- Apart from that, when I connect the camera to the PORT-4 in the schematic, I can receive data from the camera at USB 2.0 speed. (The camera supports USB 3.0 speed.) We think that this may be caused by the protection elements in the Usb lines. For this, we wanted to share with you the BOM list of the schematic page of the TUSB8042A attached. We are curious about your views and opinions here.

3-3- Currently, it works when I plug a USB2.0 keyboard or mouse into the ports.

BOM_LIST.pdf

Hi Furkan,

The hub connections should look like this.  Please note that I'm using a slightly different model of hub so there are more USB 2.0 ports.  If the hub is not connecting at superspeed the downstream devices will all drop to USB 2.0 speeds.  I will check your schematic and BOM for possible issues.

Regards,

JMMN

Hi Furkan,

The power control outputs of the hub default to active high, you should either use the TUSB2561 instead of the TUSB2560, or adjust the PWRCTL_POL pin on the hub.

Can I see the schematic / BOM for the upstream port connection?

Regards,

JMMN

Hi,

Schematic drawing of UPSTREAM port and BOM list is on page 2 of BOM_LIST pdf above.

TUSB8042A is first connected to the connector and then to the PC with a 25 cm cable. (Connector and cable are USB 3.0.)

Note: The connector and cable conform to USB 3.0 structure.

Best Regards,

Furkan

Hi Furkan,

Is the cable a standard USB 3.0 cable that does the TX to RX swap?  Can you check the line states of SSTX/SSRX if you have a scope?

Regards,

JMMN

Hi JMNN,

I can't check the status of the SSTX / SSRX lines because we have rohde & schwarz hm03004, an oscilloscope and a 1.3Ghz TRVNA 1300. What kind of test setup would you suggest we set up with these?

There is no swap condition in the cable we use. Due to the confidentiality of the project regarding the cable and connector, I cannot provide any further information. If you give your e-mail address, I can explain in more detail from there.

Best Regards,

Furkan