Hello everyone!
We're attempting to integrate a TUSB2046B hub into one our of designs and have run into some issues.
I've attached a screen shot of our schematic that we are working with. We have made the following modifications:
- Replace R10 and R11 with 10 ohm resistors
- Remove R9 and solder jumper the two pads
- Replace C6 and C8 with 7.5 pF capacitors
- Add a pull-up 15k resistor to D- (low-speed device)
- Remove R10 and connect to an RC network that holds RESET low until the clock is stable (with current C_L this is ~12 ms)
The oscillator startup time is quite long right now - approximately 10 ms. In the scope capture below (purple = oscillator, yellow = reset signal) you can see the startup behavior (we have since changed the reset timeout to 10ms).
Right now we're just attempting to get the hub to enumerate with the host computer.
We see the following output in dmesg. We also see USB traffic using our logic analyzer, but it appears that the hub does not respond.
We've checked the suspend pin, and it doesn't appear our device is in suspend.
Does anyone have any tips for how to continue debugging this issue?
