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About USB0_ID pin of OMAP-L138

RY9983
Guru 10570 points


Hello.

I would like to confirm about configuration of USB0_ID for device mode operation.
The wiki describes that the USB0_ID pin should put to NC for device mode.
http://processors.wiki.ti.com/index.php/OMAP-L13x_/_C674x_/_AM1x_Schematic_Review_Checklist#USB_2
But, there is not IPU on USB0_ID pin in datasheet (SPRS586b).

I worry whether USB operates as a host because of some noises.
Could you let me know?

- Should I worry about the noise of USB0_ID?
- If yes, should I apply the USB0_ID pin to IPU?
- Or, have IPU already set in the device?

Best regards,
RY

 

  • 0
    TI__Expert 8785 points

    I would recommend leaving the USB0_ID pin for a device floating.  Adding IPU might alter the behavior of the ID pin.

    wiki said:

    The USB On-The-Go standard introduces a new plug receptacle called mini-AB. It can accept either a mini-A plug or a mini-B plug. Mini-A Adapters allow connection to standard-A USB cables, coming from peripherals. The standard OTG cable has a mini-A plug on one side and a mini-B plug on the other (it cannot have two plugs of the same type). The device that has a mini-A plugged in becomes an OTG A-device, and the one that has mini-B plugged becomes a B-device (see above). The type of the plug inserted is detected by the state of the pin ID (the mini-A plug has the ID pin grounded while the ID in the mini-B plug is floating). (There are also pure Mini-A plugs, used where a compact host port is needed but OTG is not supported.)

    If you are operating only in device-mode and are still worried about the ID pin, you can set CFGCHIP2[USB0OTGMODE] to device mode only.  It will override any PHY values and force the USB into device operation.

    --Christina

  • 0 in reply to clam
    Guru 10570 points

    Hello, Christina
    Thank you so much for your help!
    I would like to follow your advice.
    Best regards,
    RY

  • 0 in reply to clam
    Intellectual 280 points

    Dear Christina hi,

    This post is quite old but I hope you can see my question, I have a problem with USB with c6748 DSP. I have a custom board with the present DSP really not that different from the EVM6748 as far as the DSP is concerned.

    I am trying to run a USB example (any example) using the BIOSUSB 01.10.03. I also have winXP, CCS4, BIOSPSP 1.30.01, DSP-BIOS  5.41.03.17
    Code Generation Tools 6.1.9, EDMA 3 LLD 01.11.02.05.

    The problem I see is that when I load the program I get "USB device not recognized" and the device is shown as unknown. In one example I did set the ID you mention to device but no luck. I've posted snap shots of the problem, you can see that the VID AND PID show zero.

    can you help?

    thanks george