LP-MSP430FR2476: External Resistors

Hi Kenley 

>> But if the internal pull-up resistors are enabled, is it correct that R9 and R10 are not necessary?

GPIO of MSP430FR2476 has internal pullup and pulldown resistor.

both internal and external resistor are OK on this switch circuit.

>> For MSP430FR2476, Are there any pins where customers cannot set the internal pull-up resistor in the "input" setting of the GPIO? 

Please check the data sheet MSP430FR247x Mixed-Signal Microcontrollers datasheet (Rev. C)

all GPIO can be set

>> Should they implement limiting resistors?
>> If yes, how many Ω resistors should you put in if you want to implement it?

limiting resistors is not needed.

Thanks!

Hi Xiaodong,

Thank you for your support.

If the internal pull-up is set as in the LP-MSPM0L1306 switch circuit shown in the figure below, I think that the circuit will be such that the external pull-up is not implemented and only dropped to GND.

But as you said that in the LP-MSP430FR2476 GPIO has internal pullup and pulldown resistor.
Do you mean that both internal and external resistors need to be set?
If both are set, when the external pull-up is mounted should the internal resistance be set as pull-up or pull-down?

LP-MSPM0L1306:

Regarding internal resistance, customer would like to know how to set the internal pull-up/pull-down in "Syscfg".
Also, you can select "Lower" and "Upper" for "Assigned Port Segment" in the figure below.
Could you give explanation what will happen when you set each as "Lower" or "Upper"?

Thank you and best regards,

Kenley

Hi Kenley 

But as you said that in the LP-MSP430FR2476 GPIO has internal pullup and pulldown resistor.
Do you mean that both internal and external resistors need to be set?
If both are set, when the external pull-up is mounted should the internal resistance be set as pull-up or pull-down?

because, there is the external pullup resistor in LP-MSP430FR2476, the internal pull-up or pull-down resistor is not needed to be set.

Thanks

Hi Xiaodong,

Thank you for your support!

Could you share what will happen when we change the below settings ?

I tried to search for the manual but i could not find it anywhere.

Thank you in advance.

Best regards,

Kenley

Hi Kenley

I can find the discription.

+++++++++++++++++++

Explicitly allows for upper or lower port utilization on the device. Some functions in GPIO are grouped at the segment level. Pins can be chosen to all be in a specific segment to reduce code size
Additionally, Events are set up at the port segment level. Therefore, if more complicated Event Configurations are needed, it may be necessary to separate event functionality into multiple port Segments.

+++++++++++++++++++

I think this is some update on software.

I think It should be grouped. The size of the compiled program may be different. For example, you choose to initialize GPIO uniformly instead of performing initialization one by one.

Thanks!

Hi Xiaodong,

I think customer mean that when assigned port segment change to "lower" or "upper", what will happen ? 
What does each of them do ?

Thanks and regards,

Kenley

Hi Kenley

The pins are grouped into upper and lower segments, so selecting “lower” or “upper” will filter the available pins based on that selection.
We are checking if there is any document to explain where it specifies if a pin is in the lower or upper segment
So far, I will recomment user to ignore this options

Thanks