MSP432P401R: Difference between a power-on reset and an external reset

Hello Koki,

Section 3.2 of the MSP432P401R User's Guide provides all the different types of Resets, but the external reset pin should cause a Power-On Reset (POR).  But, it sounds like you are saying that your issue persistent through a POR but is fixed with a full power cycling of the MCU.  

Is this correct?  Can you tell me about what type of issue you are seeing? 

Thanks,

JD 

Hi, JD

The external reset is operated by turning the button on and off.

However, it may not recover even if the button is turned on for a long time. MSP432 seems to be frozen.

It starts when the power switch is turned off and on again. Then when I press the reset button, the MSP432 is reset successfully.

It seems that the external reset may not work due to some behavior.

Thanks,

Koki

Hello Koki,

Do you have the reset pin pulled to VCC with a resistor?  If so, what value?

Can you confirm when the button is turned on, the voltage on the MSP432 Reset pin goes to 0v?

Conor said:

It seems that the external reset may not work due to some behavior.

If the PIN_SRC bit in the NMI Control and Status Register was changed from the default value of 0 to 1 it will configure the RSTn/NMI pin as a source of NMI. That could explain why the external reset doesn't work.

From the MSP432P4xx SimpleLink Microcontrollers Technical Reference Manual (Rev. I) :

Hi, Dennis

Dennis Lehman said:

Do you have the reset pin pulled to VCC with a resistor?  If so, what value?

The figure below shows the resistance value and capacitance value to the reset pin.

Dennis Lehman said:

Can you confirm when the button is turned on, the voltage on the MSP432 Reset pin goes to 0v?

I confirmed that the voltage transitions to 0V when the reset button is pressed.

Thanks,

Koki

Hi, Chester

The problem may or may not occur with the same software, so it is unlikely that it is a register value problem.
We will check the value of register and report the result later.

Thanks,

Koki