Backdoor problem

[lyz]

Problem1:

I use this example code, disable successfully, but the S32K144 chip reset when i use J-Link to connecting S32K144 core by J-Flash. example as follow:

lyz_0-1667900497044.png

Can i use J-Link to connecting S32K144 core by J-Flash when Using a backdoor key to unlock security? Can the chip reset?

Problem2:

when Using a backdoor key to unlock security, as follow, manual config

lyz_1-1667900831332.png

but, the config of example code, as follow:

lyz_2-1667900979823.png

Both is different. I try the config of manual, do not disable secure.

please tell me the answer, thanks!

[Robin_Shen · Accepted solution]

Hi lyz,

A1. When test that example, the chip is secured after reset.(notice "Un-securing the MCU using backdoor key access") When you want to connect it, mass erase will blank the chip, no code in the chip will cause periodic resets. 

Un-securing the MCU using backdoor key access.png

A2. FTFC->FCCOB[3]  point to FCCOB0 which used to fill with Flash command(You can refer to the source code of AN5401SW\3_Basic_operations)

FTFC_FCCOB[3] FCCOB0 Flash command.png

Best Regards,
Robin
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[lyz]

thank you very much!
I know this. But forget FTFC->FCCOB[3] point to FCCOB0