HX2VL-CY4608 Host cannot access devices in Bus power mode

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Anonymous
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Hello,

I'm evaluating HX2VL-CY4608 development bord of CY7C65632. Host can access devices in self-power mode using 5V DC supply. But it cannot access them in bus-power mode. I appreciate your adivce in advace.

1-1 CY4608 board setting

      J5(I2C_EEPROM_PWR): short, SW1: 5V_Internal_Regulator, JP1 open

      picture of board is attached

1-2 EEPROM configuration

    Based on 4port_HX2VL.iic downloaded from cypress web site.

    remobal port      :00

    number of ports :04

    maximum power :FA(500mA)

2 test result

2-1 In self power mode

     Host can access all 4 ports.

2-2 In bus-power mode

    Host detect 2.0hub CY4608 by windows device manager as USB controller.

    It can access mouse(pointing device).

    But Host cannnot access devices(USB memory , USB camera). PC issues error message "Power exceed USB hub power supply ability".

Regards,

S. Kamae

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1 Solution

Hello S.Kamae-san,

As seen from the below image of yours, the USB camera is configured for 200mA of current which cannot be provided by a bus-powered hub. Kindly, let me know if there are any devices that require less than 100mA of current and still fail on the bus-powered hub.

USBView_2_2.jpg

Best regards,

Srinath S

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10 Replies
SrinathS_16
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1000 replies posted 750 replies posted 500 replies posted

Hello S.Kamae-san,

In bus powered mode, the USB 2.0 hub can deliver only 100mA per port. A device that requests more than this power will not be enumerated on the downstream ports. To connect such devices, the hub must be configured in the self-powered mode.

Best regards,

Srinath S

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Anonymous
Not applicable

Hello Srinath S-san,

Thank you for quick response.

I understand specification 100mA per port for USB2.0 and 180mA for USB3.0. And current of USB camera is 82mA and available bus-powered USB hab can access them. I hope there is some board setting or EEPROM configuration that I don't know.

I appreciate your further adivice.

Regards,

S.Kamae

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Hello S.Kamae-san,

Can you please use the USBView software to list the descriptor details of the USB Camera and share the screenshot of the same?

Best regards,

Srinath S

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Anonymous
Not applicable

Hello Srinath S-san,

USBView screen shot are captured. They are attached.

Please give me some comments.

Best Regards,

S. Kamae

USBView_1_1.jpg

USBView_1_2.jpgUSBView_1_3.jpg

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Hello S.Kamae-san,

Please find the image below which indicates that I have connected a USB pen drive that requires more power than what the bus powered hub can deliver. Kindly, check if you get similar error messages in the USBView software when connecting the camera to the hub.

pastedImage_0.png

Best regards,

Srinath S

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Anonymous
Not applicable

Hello Srinath S-san,

I got screenshot of USBview when windows issue error message in connecting USB camera. Though USBview doesn't issue any worning/errors and Connection status keeps NoDeviceConnected.

Autorefresh is set in USBview. Do I have to set any option in USBview?USBView_1_4.jpg

Best Regards,

S. Kamae

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Hello S.Kamae-san,

I would like to see the descriptor details of the device that is failing. Can you please connect the camera to the PC host directly or to a self-powered hub and share the USBView results?

Best regards,

Srinath S

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Anonymous
Not applicable

Hello Srinath S-san,

Thank you for supporting.

The images are captured when the camera is connected to PC host. Please find the images attached.

USBView_2_1.jpgUSBView_2_2.jpgUSBView_2_3.jpgUSBview_2_4.jpgUSBview_2_5.jpgUSBview_2_6.jpgUSBview_2_7.jpgUSBview_2_8.jpgUSBview_2_9.jpgUSBview_2_10.jpg

USBview_2_11.jpg

Best Regards,

S. Kamae

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Hello S.Kamae-san,

As seen from the below image of yours, the USB camera is configured for 200mA of current which cannot be provided by a bus-powered hub. Kindly, let me know if there are any devices that require less than 100mA of current and still fail on the bus-powered hub.

USBView_2_2.jpg

Best regards,

Srinath S

Anonymous
Not applicable

Hello Srinath S-san,

Thank you very much for solving my problem.

I will check the camera vendor if they can change value of discriptor or use it in self-power mode.

This thread is closed.

Best Regard,

S. Kamae

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