Pins Tool: support termination of unused pins

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Pins Tool: support termination of unused pins

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danielholala
Senior Contributor II

Hi there,

most MCU data sheets recommend to properly terminate unused pins, see, e.g., LPC552x datasheet.

For pins with GPIO function this can be achieved by way of configuration:

  • select the GPIO function in the IOCON register
  • select output in the GPIO DIR register, and
  • write a 0 to the GPIO PORT register for that pin.

This should be done for all GPIO pins,  even those not bonded out on smaller packages.

Does the Pins Tool provide a function to automate this configuration process? If not, I suggest to consider to add this function to Pins Tool.

Thanks.
Daniel

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Petr_H
NXP Employee
NXP Employee

Hi,

Currently, the pins tool provides the function to create a routing for unused pins via the menu command Pins > Create default routing, which shows dialog, where you can select the option "Only items not routed":

Petr_H_0-1698830957677.png

This generated a new function group with all pins that are currently not routed. However, this function sets the pins the default 'disabled' function. If you'd like to route them as GPIO/output, you need to change this manually afterwards.

Thank you for the suggestion, we will discuss this with team to consider simplifying the task.

Regards

Petr Hradsky

Config Tools Team

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danielholala
Senior Contributor II

Hello @Petr_H ,

I appreciate your response. I did not know this command. However, I also don't know what exactly it does. This is a snippet of the result after running this command:

danielholala_0-1699444808761.png

I don't understand why some GPIOs are set to "disabled" while others are configured as GPIOs.

Whatever this function does, it is not what the Data Sheet recommends in section 6.1.2 "Termination of unused pins".

Thank you for forwarding my suggestion. I hope that the team will figure out a way to automatically support termination of unused pins according to the data sheet for the benefit of all users of the Pins Tool.

Best regards,
Daniel

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Petr_H
NXP Employee
NXP Employee

Hi,

I'm sorry for the delay. I have checked it and the function actually does what it's named for - it routes the pins to their default after-reset routing. In this case, it's Disabled for some pins and GPIO for the others.

I agree that it's not what datasheet mentioned, but currently our tools do not have information about that setup in their database, so we cannot provide such functionality directly. We will follow up on this improvement for next versions.

Best regards

Petr Hradsky

Config Tools Team