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Hello Wesley,

Are you using a pullup resistor of 1.5 kΩ on DP0?

I attached usbview utility, you may want to install this tool, which you then allow to get more information about an USB device. Select the item (Generic USB Hub) in the left window and it will allow its descriptors to be read in the right window. Please provide a capture. 

Regards,
Joel usbview.zip

Hello Wesley, 

TUSB2077 is Full speed (12Mbps - megabits per second ) hub, not High speed (480 Mbps). Hence when you connect your mass storage stick behind it, your mass storage stick has to work in Full speed mode. While you connect your mass storage stick directly to your PC, your stick should be working in High speed mode. This explains why you are getting slower speed when you attach your stick behind TUSB2077 hub.

You can use USBView as suggested by Joel to look at descriptor and speed.

Hope this helps.

Thank you,

Bhaumik

Hey Joel,

Thanks for your response, i am using a 1.5k ohm pull-up resistor connected to the DP0PUR pin of the TUSB2077.

Hey Bhaumik,

Thanks for responding, what i don't understand is why i'm getting 1 Mbps instead of a speed closer to 12 Mbps. Right now i think that my device is running at low speed (1.5 Mbps) but i might just be missing a piece of information here. 

Hello Wesley,

There are 3 different speeds according to USB2.0 specification : Low speed (1.5 Mbps), Full speed (12 Mbps) and High speed (480 Mbps).

High speed capable devices (such as Mass storage stick) work in High speed mode when connected behind High speed hub and works in Full speed mode when connected behind Full speed hub.

Now, read my previous post again. When you directly connect your device behind your PC, your device works in high speed mode. That's why you are getting more speed performance. But when you connect your device behind TUSB2077 hub (which is Full speed hub), your device has to work in full speed mode. That's why you are getting lower performance in this case.

Cheers,

Bhaumik