The TUSB2077 hub is not working as a host ISP1504?

Hello Gabriel,

By specification, there should not be any compatibility issue between the TUSB2077 and the ISP1504.

Can you share your schematics to see if there is something missing?

Regards.

5670.P-CAD EDA - [Sheet1].pdf7142.P-CAD EDA - [Sheet2].pdf

Hello Gabriel,

What are the symptoms of the non-working hub?  Is it enumerated?  Are the downstream devices recognized? Does it got enumerated and then it crash? etc....

Regarding the schematic, there are a couple of thing I would like you to try:

1) You are using the TUSB2077 in the GANGED mode, so all the OVRCUR terminals must be tied together, in addition I recommend pulling them up through a 15K resistor.

2) Place a 22pF capacitor to Gnd on the DP0 and DM0 terminals, in addition, I can't see in the sch if there is a 30 ohm series resistor on DP0 and DM0, if not, place them.

3) For the RC circuit you are using for resetting the TUSB2077, make sure the values of R# and C# are so that make a 1.5 to 2 ms long pulse (a 20K with 1uF is recommended)

4) The capacitors network shown in your schematic (C4 to C33) are placed backwards, perhaps is just matter of the symbol you are using in your schematic but is worth to check that.

If you can tell in more detail what is the failure like, it will be very helpfull.

Regards.

I am using only part of the hub, the rest of the circuit of the file was not mounted yet.
The hub has been tested on several PCs and it worked perfectly, but to turn it into a pci to usb host ISP1504 has one, it is not recognized, this card runs Angstrom Linux, and the manufacturer told me that type devices keyboard, mouse and TUSB2077 not work in this host, I found odd and decided to ask directly to the staff of Texas (you guys), according to them is that the host and the hub is 2.0 is 1.1 ...

Hello Gabriel,

The fact that the host is USB 2.0 compatible and the TUSB2077 is USB 1.1 compatible will not cause tha hub to stop working.  USB 2.0 is fully backwards compatible with USB 1.1 specification.

If your hub configuration is working on another systems, then a host side issue is more likely.

Can you check the integrity of the signals DP/DM  going from the host to the TUSB2077? (differential impedance, swing voltage,etc.)

You can check the section 7.1 of the USB 2.0 specification for signal compliance.

Regarding to the Angstrom, any operating system that has native USB stack support should include a HUB driver as part of that stack.

Regards.

Hello, Elias
Thank you so much attention, but unfortunately the TUSB not work, I made a new layout using the uPD720114 and is working perfectly

Hi Gabriel,

The uPD720114 is a USB 2.0 hub controller, not a USB 1.1 hub controller like the TUSB2077a device that may explain why the ISP1504 (OTG Host controller) does not have any issues with it.

Regards,

Julie