TUSB2046IBVF: USB Hub, Getting Started

Does hub upstream working?, did you see c6Mhz clock on pin 30?

Best

Brian

The 6Mhz clock is working.  All power and GND is accounted for.  The only thing I've tried to connect to is DP0 and DM0.

can you take DP/DM waveform when plug to PC?

Best

Brian

No waveform from PC to DP/DM.

Did you see DP is high, then DM should change status too.

Best

Brian

I saw trash on DP nothing was on DM.  So I removed the 22 ohms in-line protection resistors to get a raw look at the USB signal.  Nothing.  No heartbeat or wake-up command, nothing.  Then I read about how USB works and that there must be a pull-up resistor on DP in order to have positive differential voltage.  Well that makes sense, plugging in a USB device wakes up the host and a low to high signal could do that.  Then I returned and placed the 22-ohm inline resistors (U401 & U402) back on the board.  That shorted out the 3.3V rail (crap!).  Now I have another board populated with nothing but the components on the schematic you have in your possession.  

Stand by for an update after that is done...

Thank you,

Brian,

C411 has shorted to ground.  Removing that cap make my PC say that it cannot identify the chip.

I thought you already have 1.5k pullup on DP0, if C411 as shorted, then  no .3 supply for the hub.

Best

Brian

Right.

R401 and R402 was removed by me (my bad).  R401 and R402 were reinstalled, C411 was removed and there was communication from the PC to the TI chip.  The PC did not recognize the chip as a USB hub.

Brian,

Per your request see the attached waveform.  Now this happens about 5 times and then the PC tells me it doesn't recognize the hub.

Also, I've tried other interactions and got different results.  I plug the hub into my PC and this waveform happens DM stays low.  I plug the hub into the Beagle Board and DM goes to 5 volts and no square wave.  I plug a different computer into the hub and it does the same, DM goes to 5V and has no square wave.  Why is that?

pin 4 is ID pin, if Gnd means it's host device, but 2046 is hub. So pin4 shoud be floating.

Done.

Still USB Device not reconized.

The new wave for looks much cleaner.

do you have USB analyzer to take trace? or send full schematic ?

Best

Brian

I do not have a USB analyzer.  I do have the full schematic.  It seems the chip is acknowledging with no results.  Your file upload isn't easily used so...

hard to read, can you accept my friendship request and send to  priivate message?

Best

Brian

Done.

Can you send with private message?