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MSPM0G3107: Clock and unused pins settings

Kenley
Intellectual 1795 points
Part Number: MSPM0G3107
Other Parts Discussed in Thread: SYSCONFIG,

Tool/software:

Hi team,

Could you please give feedback on the following questions from my customer?

1. We would like to ask you about clocks.
What is the difference between LFCLK and ULPCLK? I would like you to tell me how to use it properly.
Also, when is "MFCLK" used? Please tell me how to use it with "MCLK". 

2. We would like to ask you a few questions about handling unused pins.
① As described in the Comment column below, do they have to assign output and input to GPIO for all unused pins? Or is it possible to simply not assign pins in SysConfig?
② What is the value of this resistor when internal pullup/pulldown is used?
③ Is it correct to understand that both internal pullup and pulldown are disabled (i.e. IO pin is Hi-Z) until the configuration of the user program?
④In the Japan version of the hardware development guide, it is written in the "Note" part of the table below that you can refer to the connection guidelines for unused pins of "PAx", but they could not find it.
Where can they check from?

Thank you in advance.

Best regards,

Kenley

  • 0
    TI__Mastermind 46765 points

    Hi,

    1. The ULPCLK is the bus clock for peripherals in the PD0 power domain. It supports operation up to 40 MHz and is derived directly from the MCLK tree through a clock divider. LFCLK provides a continuous 32-kHz clock to a variety of peripherals on the device. You can find more details in the TRM chapter 2.3.2

    Some analogy peripherals need use MFCLK as its clock source like ADC. You can check each peripheral's clock reference page for more details.

    2.1 There is a function in Sysconfig to help configure all the unused pins.

    2.2 What register?

    2.3 Yes. 

    2.4 Not understanding the question. Are they asking what "PAx" stands for? PAx stands for PA0 to PA31 pins. 

    Best regards，

    Cash Hao

  • 0 in reply to Cash Hao11
    TI__Intellectual 1795 points

    Hi Cash,

    Thank you for your support.

    Regarding 2.1, yes i know there is function in sysconfig, but we are asking about do we have to check all the pin that is unused ?

    Or is it okay to let them unchecked when it is unusued ?

    Best regards,

    Kenley

  • 0 in reply to Kenley
    TI__Mastermind 46765 points

    Hi,

    For the best current consumption optimization, it is recommend to check all the unused pins.

    Best regards,

    Cash Hao 

  • 0 in reply to Cash Hao11
    TI__Intellectual 1795 points

    Hi Cash,

    Thank you for your support.

    Regarding 2.4, seems like there is note as following on mspm0g3107.pdf "6.4 connecting unused pins".

    " Any unused pin with a function that is shared with general-purpose I/O must follow the "PAx and PBx" unused pin connection guidelines."

    Could you show which page should customer refer to ?


    Please let us know if you have any guidelines. 

    Thank you,

    Kenley

  • 0 in reply to Kenley
    TI__Mastermind 26390 points

    Hi Kenley,

    The image you shared is the correct one. The footnote is referencing special pins like SWDIO, SWCLK, analog pins (COMP, OPA, DAC, ADC), and future looking to other devices which can also be a general purpose IO pin (they will have a PA or PB assigned to them if you look at the pin attributes table in the datasheet). If you are not going to use these pins it is recommended to set them to output low.

    Regards,
    Luke

  • 0 in reply to Luke Ledbetter
    TI__Intellectual 1795 points

    Hi Luke,

    Thank you for your support.

    I know we can set unused pins as low with Syscfg on CCS.

    Can internal pulldown be enabled and set to low also with this setting?

    Or do customer need to enable internal pulldown on the register, or connect a pulldown resistor to an external pin and set it low? a

    If they need to connect an external pull-down resistor, please let us know the recommended resistor value. 

    Thank you,

    Kenley

  • 0 in reply to Kenley
    TI__Mastermind 46765 points

    Hi,

    Customer can configure internal pulldown for unused pins in Sysconfig. 

    Best regards,

    Cash Hao