ISSUE: Can't detect USB HUB on PC

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masu_1341616
Level 5
Level 5
Distributor - TED (Japan)
10 solutions authored 10 likes received 25 sign-ins

Hello,

We evaluate CY4608M Development kit and USB2514(SMSC).

Only CY4608M have connectivitie issue on our test.

When "FIRST CONNECTION" to usb cable, this issue could find and This issue depend on cable length. 

The test method is as follows.

1. CY4608M is in bus power mode, output 4 port is not connected, output side electrolytic capacitor (120 μF × 4)

    is to be discharged completely.

2.The PC (Win 7) starts the device manager and "Universal serial Bus controller "is opened and displayed.

3.Connect the board and the PC with a USB cable.

4.If you check the PC's device manager, it recognizes it as a USB HUB "!" Mark is displayed and the property shows "Not working".

    * Once you unplug the USB cable and reconnect it will work normally.

We concerned power circuit of CY4608M.

When hiside power swich become ON, the  The Current charge to output side electrolytic capacitor (120 μF × 4).

during this case, voltage drop down momentary.

We are thought to be the cause of this.  USB2514(SMSC) don't have same issue.

Please let me know workaround or any advice.

Thanks

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1 Solution
prc_1505996
Level 4
Level 4

Hi,

          For me, it looks like more of a test setup issue (could be cable or PC. I doubt cable). This kit is USB compliant, that means the kit has passed multiple tests mandated by USBIF (Electrical, CV and interop tests...). What you are testing is already covered in the interop tests and, your test case is much simpler as there are no devices connected to the DS ports.

         This issue can be due to the CY4608 input capacitance and the cable inductance working together during the first plugging (due to higher di/dt rate). When I say input capacitance, 4X120uF are not included as these caps will come into picture only after detecting devices on the DS ports (at least as per the spec). This can be verified by removing the caps from the board or testing with charged & discharged caps. The subsequent connects will experience lesser di/dt, therefore the cable voltage drop as well. Are you using a certified cable ? What is the length of your cable? Can you reproduce the issue with a shorter cable?

        Adding a soft start circuit at US port VBUS will solve this problem, I believe this is not a board issue.

Tnx,

PRJI

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5 Replies
masu_1341616
Level 5
Level 5
Distributor - TED (Japan)
10 solutions authored 10 likes received 25 sign-ins

Additional Information about CY4608M

ch1:+5V

    Drop down to less than 3.3V.

ch2:+3.3V

ch3:+5V

波形.jpg

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Anonymous
Not applicable

Hi Masahito-san,

After the power switch is turned ON, there might be loading affect due to the cable used.

And the yellow mark might be due to driver binding. Please make sure to bind the Hub to "Generic USB Hub" if the Hub is trying to bind to Cypress vendor driver. If externally connected EEPROM is empty, the Hub will try to bind to the Cypress Vendor mode.

Regards,

Anil

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Anonymous
Not applicable

Hi Anil,

Please let me confirm your response.

>After the power switch is turned ON, it is clear that there is loading affect which means the load is drawing more current.

⇒ Do you mean the voltage dropped is normal operation when Power switch turn ON? 

Could it be considered that voltage dropped is the root cause of this issue?

If yes, could you investigate the "limit voltage" that if the VCC_5V dropped lower than that "limit voltage", the issue should occured?

>And the yellow mark might be due to driver binding.

>Please make sure to bind the Hub to "Generic USB Hub" if the Hub is trying to bind to Cypress vendor driver.

>If externally connected EEPROM is empty, the Hub will try to bind to the Cypress Vendor mode.

⇒ Have you reproduce this issue in CY4608M? If no, could you please try to reproduce with long length USB cable (Eg. 1.5m or 2m). The step is described above.

Please tell us if there are any workaround for this issue?

Regards,

Tran.

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Anonymous
Not applicable

Hi Anil,

>Please make sure to bind the Hub to "Generic USB Hub" if the Hub is trying to bind to Cypress vendor driver.

>If externally connected EEPROM is empty, the Hub will try to bind to the Cypress Vendor mode.

I've tried 2 test with CY4607M at my end.

1. With EEPROM (Place jumper on J5,J6)

2. Without EEPROM (Remove jumper on J5,J6 or even remove EEPROMs)

The result is the same, both case is bind to Intel driver iusb3hub.sys ( See attached image )

Please confirm

Regards,

Tran.

WS000762.JPG

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prc_1505996
Level 4
Level 4

Hi,

          For me, it looks like more of a test setup issue (could be cable or PC. I doubt cable). This kit is USB compliant, that means the kit has passed multiple tests mandated by USBIF (Electrical, CV and interop tests...). What you are testing is already covered in the interop tests and, your test case is much simpler as there are no devices connected to the DS ports.

         This issue can be due to the CY4608 input capacitance and the cable inductance working together during the first plugging (due to higher di/dt rate). When I say input capacitance, 4X120uF are not included as these caps will come into picture only after detecting devices on the DS ports (at least as per the spec). This can be verified by removing the caps from the board or testing with charged & discharged caps. The subsequent connects will experience lesser di/dt, therefore the cable voltage drop as well. Are you using a certified cable ? What is the length of your cable? Can you reproduce the issue with a shorter cable?

        Adding a soft start circuit at US port VBUS will solve this problem, I believe this is not a board issue.

Tnx,

PRJI

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