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MSPM0C1103: How to switch I/O between Hi-z and Low outputs

K.Z
Expert 2490 points
Part Number: MSPM0C1103

Tool/software:

Hi All,

Is it possible to set the I/O of the MSPM0C1103SDGS20R to HiZ (both P and N are off) and L output (P is off, N is on)?

I looked in the TRM and found a Bit named HIZ1 in the GPIO configuration register.
Is this bit enabled only for 5V tolerant IO PA0, PA1?
If this is valid for all IOs, I could read that other IOs can be open-drain with this bit.

Best Regards,

Ito

  • +1
    TI__Genius 10611 points

    Hi Ito,

    You can configurate normal GPIO to Hi-Z mode.

    Please use below API to change to HI-Z mode. In this mode GPIO is like open-drain, and you can use external pull-up resistor to output high voltage.

    DL_GPIO_initDigitalOutputFeatures(GPIO_GRP_0_PIN_0_IOMUX,
		 DL_GPIO_INVERSION_DISABLE, DL_GPIO_RESISTOR_NONE,
		 DL_GPIO_DRIVE_STRENGTH_LOW, DL_GPIO_HIZ_ENABLE);

    Use below code to change to use internal pull-up/pull-down resistor mode, which is you said normal output mode.

     DL_GPIO_initDigitalOutput(GPIO_GRP_0_PIN_0_IOMUX);

    Regards,

    Zoey

  • 0 in reply to Zoey Wei
    Expert 2490 points

    Hi Zoey,

    In order to use it as an open drain,
    I need to use a pull-up resistor external to the device, correct?
    Is there a way to make an open drain without increasing the number of components?

    Best Regards,

    Ito

  • +1 in reply to K.Z
    TI__Genius 10611 points

    Hi Ito,

    No, I mean if you set to Hi-Z mode, the GPIO will be used like open-drain.

    But if you want to output high voltage while in Hi-Z mode/open-drain mode, you need to use external pull-up resistor, which is the open-drain features just like PA0 and PA1.

    Regards,

    Zoey

  • 0 in reply to Zoey Wei
    TI__Genius 10611 points

    Also, you can use internal pull-up as HI-Z is enabled.

  • 0 in reply to Zoey Wei
    Expert 2490 points

    Hi Zoey,

    Thank you for your reply.

    Zoey Wei said:
    But if you want to output high voltage while in Hi-Z mode/open-drain mode, you need to use external pull-up resistor, which is the open-drain features just like PA0 and PA1.

    For 3.3V output, is an external pull-up resistor necessary?

    Best Regards,

    Ito

  • 0 in reply to K.Z
    TI__Genius 10611 points

    Hi Ito,

    You can enable internal pull up resistor which is 40k. Also you can use external pull-up resistor~

    Regards,

    Zoey