Hello,

The schematic looks correct, please double check the physical connections, Vcc, XI, OVRCUR#, RST#.
Is SUSPEND high?

Regards

Dear Elias Villegas,

 

Thanks for the prompt reply to my question.

 

I've done the timing testing on oscilloscope.

 

Based on the recommended value of 15K and 1uF for the Reset pin, I found that the Rise Time at the reset pin is about 30mS, much longer than the 100uS to 1ms recommended timing.

 

I changed the capacitor to 10nF, the Rise Time is about 500uS.

 

Attached below is the timing diagram I captured on my scope.

 

 

The Ch 1 signal (Yellow) is the +3V3 signal.

 

The Ch 2 signal (Blue) is the XTAL1 signal.

 

 The Ch 3 signal (Purple) is the Reset signal.

 

The Ch 4 signal (Green) is theSuspend signal.

 

OVRCUR signal is at 3.3V.

 

From the waveform, it can be seen that Suspend signal goes to suspend mode after 2 seconds.

 

Any idea what could be my mistake in the circuit? Thanks for the help.

 

Regards,
Foo DF.

Hello,

It looks like the Hub is not responding to the USB host so the Host is sending it to suspend, I would increase the power-on reset time, the scope shows the crystal is not stable before Reset is de-asserted, can you increase the power on reset time to a couple of milliseconds?
Check the DP0 and DM0 physical connections as well.

Once the hub is sent to Suspend, does a hard reset clears the issue?

Regards

Thanks for the prompt reply.

I changed the resistor to 30Kohm and capacitor to 1uF.

Below is the timing diagram I captured on the scope:

As can be seen from the photo, the power on reset timing has been increased but the Suspend signal goes high after 2 seconds.

Below is the timing diagram on hard reset through push switch, Suspend signal goes high after reset. 

I've checked that DP0 and DM0 pins are connected to D+ and D- respectively.

What else should I check to solve the problem? Thanks.

Hello,

Thanks for making the modifications.

What is the state of the OVRCUR# terminals?

Double check the 1.5k pull-up on DP0.

Are you using windows? Can you update the USB driver?

Do you have USB downstream devices connected? If not, can you connect one?

Can you use the USBView and take a screen shot for me?

You can download the USBview from here 

Regards

Hello,

Thanks for the prompt reply.

Below is the timing diagram with DP0 signal (purple):

The Ch 1 signal (Yellow) is the +3V3 signal.

The Ch 2 signal (Blue) is the XTAL1 signal

The Ch 3 signal (Purple) is the DP0 signal.

The Ch 4 signal (Green) is the Suspend signal

OVRCUR signal is at is following the 3.3V signal and remains High.

If you were to look at the signal upon force reset I captured earlier as shown below. Based on the picture, the oscillation cycle period is about 15mS, which worked out to be 1/15mS = 67Hz,  this is not right as the crystal oscillator used in the circuit is 6MHz.

What could be the mistake? Thanks.

The amplitude of the XTAL1 looks low as well.

I can't see the value of the load capacitors but try reducing them.
Can you tell what is the lot code of this device? I want to look on the production records, if you are not sure which one is the lot code please post a picture of the top marking of the device.
Double check your layout on the crystal section, look for short circuits.

Regards

Dear Elias Villegas,

Thanks for the reply again.

The crystal (MULTICOMP  HC49SM-6-30-50-60-30-ATF  CRYSTAL, HC-49/4HSMX, 6.0MHZ) I used was bought from Element14:

sg.element14.com/.../1667011

The load capacitors are at 27pF each.

Regards,

Foo DF.

Hello,
Have you made further progress?

Please update the windows's USB driver.
The Hub going into suspend is not incorrect if there is no downstream devices attached, does it happens if you connect a USB downstream device to the Hub?
Regards

Hello,

I connected my USB hub with USB thumb drive, my Window 7 PC displays "USB Device Not Recognized" on my Device Manager.

I'm not able to download  the USBView.exe file from msdn.microsoft.com, can you sent this file to me to try out? Thanks.

Hello,

Please update the windows's USB driver.

The Hub going into suspend is not incorrect if there is no downstream devices attached, does it happens if you connect a USB downstream device to the Hub?

Does it happens with multiple USB thumb drives?

Here is the usbview sdksetup.zip

Hello,

I managed to installed the USBview program and run it on my PC.

Below is the screen shot from USBview,

What could be the mistake in my USB Hub? 

Thanks and regards,

Foo DF.

Hello,

I managed installing the USBview on my PC, below is the screenshot :

It seems that my USB hub is not responding at all, what could be the mistake in my board?

Thanks and regards,

Foo DF.

I don't see the TUSB2046 on the USBview snapshot, also, you have two USB Host controllers, can you uninstall the renesas?
Regards

Hello Duon,

It seems to be a mistake in USB connectors. In you schematic DP is connected to D-, that's wrong.

Thanks Anton Egorov  for pointing out my mistakes. I've made the correction to the DP and DM to D+ and D- connections. I was hopeful my USB hub should be working properly now but when I connect to my PC with thumb drive by running the USBview debugger at the same time, the USBview debugger show no USB is connected.

I remembered reading from the forum that the reset timing is very critical to the USB operation, so I experiment it by replacing the 15K resistor with a 200Kohm trimmer, with capacitor remains at 100nF. Below are the timing diagram from different trimmer settings :

The Ch 1 signal (Yellow) is the +3V3 signal.

The Ch 2 signal (Blue) is the XTAL1 signal.

The Ch 3 signal (Purple) is the Reset signal.

The Ch 4 signal (Green) is the Suspend signal.

1st trimmer (lowest resistance) setting:

2nd trimmer resistance setting:

3rd trimmer resistance setting:

4th trimmer resistance setting:

5th trimmer resistance setting:

6th trimmer resistance setting:

7th trimmer (highest resistance) setting:

Even with the above different trimmer settings, I still could not get my USB hub recognized by by PC, any thing else should I try to correct this TUSB2046B "USB Device Not Recognized" problem?

Anyone one with working experiment with TUSB2046B USB hub would like to share your experience? Thank you very much.

Thanks Anton Egorov  for pointing out my mistakes. I've made the correction to the DP and DM to D+ and D- connections. I was hopeful my USB hub should be working properly now but when I connect to my PC with thumb drive by running the USBview debugger at the same time, the USBview debugger show no USB is connected.

Texas Instruments recommends a minimum of 100 μs to a maximum of 1 ms of reset timing. By the way, I've monitored that the crystal oscillator is running at 6MHz on oscilloscope. It seems that the reset timing is very critical to the USB operation, so I experiment it by replacing the 15K resistor with a 200Kohm trimmer, with capacitor remains at 100nF. Below are the timing diagram from different trimmer settings :

The Ch 1 signal (Yellow) is the +3V3 signal.

The Ch 2 signal (Blue) is the XTAL1 signal.

The Ch 3 signal (Purple) is the Reset signal.

The Ch 4 signal (Green) is the Suspend signal.

1st trimmer (lower resistance) setting:

1st trimmer (higher resistance) setting:

Even with the above different trimmer settings, I still could not get my USB hub recognized by by PC. From the above picture, it seems that the crystal only starts oscillate 2.5mS after VCC is applied, this is definitely longer  than recommended reset time of 1mS, If I adjust my trimmer to faster reset rise time, the crystal has not even oscillate yet (Picture 1). On the other hand, if I adjust my trimmer to slower reset rise time, the Suspend line will goes high after 10mS (Picture 2).

Any thing else should I try to correct this TUSB2046B "USB Device Not Recognized" problem?

Anyone one with working TUSB2046B USB hub would like to share your experience? Thank you very much.