MKE04Z64VLD somtime freeze during Power up

[eyalsaban]

Hi All ,

we have design based on MKE04Z64VLD   , the MCU  is powered by 5V and the reset PIN is connected to Supervisor 

MCP120T-460I/TT.

on power up sometimes , the MCU enter some freeze state and can exit this state only using additional RESET or power cycle .

the MCU toggle some LED as Keep alive indication , when it's on freeze state the LED doesn't change it's state .

any idea what could cause such issue  ?

[kerryzhou · Accepted solution]

Hi Eyal Saban,

   Please check your VDD and the reset pin wave by referring this post:

KE/KEA POR Sequence and ICS Module Investigation 

   If the power on and reset sequence is changed, the boot may have the problem.

   Besides, please also check your NMI pin, you can connect an external pull-up resistor, just to exclude the NMI is pulled low factor.

Have a great day,
Kerry

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

[eyalsaban]

Hi Kerry ,

Thanks for your quick response , indeed the pull-up resistor to NMI pin solve the issue.

[kerryzhou]

HI Eyal,

   You are welcome, that's very good to hear the external pull-up in NMI solve your problem.

   If you don't have any other question about this topic, please help to close this case by marking the correct answer.

   Thank you!

Have a great day,
Kerry

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

[eyalsaban]

Will do.