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TM4C1232H6PM: USB data line termination

Alexandr Zvyagin
Prodigy 25 points
Part Number: TM4C1232H6PM

Tool/software:

Hi

Is a termination required for the data lines D+ and D- of the USB (Pin number 43 and 44)?

Thanks

  • +1
    TI__Guru**** 191886 points

    Hi,

      No, you do not need termination resistors on D+ and D- as these have been added internally. Please refer to the datasheet for details. 

    Note:

    When used in OTG mode, USB0VBUS and USB0ID do not require any configuration as they
    are dedicated pins for the USB controller and directly connect to the USB connector's VBUS
    and ID signals. If the USB controller is used as either a dedicated Host or Device, the
    DEVMODOTG and DEVMOD bits in the USB General-Purpose Control and Status
    (USBGPCS) register can be used to connect the USB0VBUS and USB0ID inputs to fixed
    levels internally, freeing the PB0 and PB1 pins for GPIO use. For proper self-powered Device
    operation, the VBUS value must still be monitored to assure that if the Host removes VBUS,
    the self-powered Device disables the D+/D- pull-up resistors. This function can be
    accomplished by connecting a standard GPIO to VBUS.


    The termination resistors for the USB PHY have been added internally, and thus there is
    no need for external resistors. For a device, there is a 1.5 KOhm pull-up on the D+ and for
    a host there are 15 KOhm pull-downs on both D+ and D-.