I am using this Microcontroller NXP MCU

I am trying to understand the RESET Section of the microcontroller.

1.On page 83, it is given as MCU reset is a bidirectional pin. So, It can drive other peripherals to reset and it can also be reset by other peripherals, right?

2.I was not able to find in the datasheet that this RESET pin is in open drain configuration? Can you please help me where to find this information for the pins?

  1. How to check if the reset pulse duration is not long at power up?

  2. What does WFRST mean? And how can I calculate the minimum current required to pull reset pin low?

I am unable to understand certain terms mentioned in the datasheet as this is my first project in microcontrollers. That's why so many simple queries. Sorry. Please help


  • \$\begingroup\$ Regarding reset pulse length, MCUs are picky which decoupling cap you place on the reset pin. This should be mentioned by the manufacturer through some datasheet or reference design. It will be adapted to suit the reset pulse length. \$\endgroup\$ – Lundin Jan 25 at 12:51

1) Yes it is bidirectional

2) It is not specifically mentioned but it is otherwise obvious from the electrical characterisrics for example, it is an input than can drive low.

3) Why would reset pulse length matter? But an oscilloscope or logic analyser will display the reset length.

4) WFRST can be searched from the datasheet, it is maximum pulse length filtered (ignored) by reset pin. Minimum current is in elelectrical characteristics (Max 150 microamps), the voltage must be pulled below 0.35*Vdd.


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