Access to RAM outside section

[markus1]

Hello,

I would like to keep some information in RAM during a reset to handle the issue that caused the reset. Therefore, I reduced the section of m_data_2 of my S32K116 by 0x20 bytes.

Accessing those bytes with a debugger attached and handling SW-resets works fine.

Anyway, if I remove the debugger, the MCU cannot pass the line where the memory outside the section is accessed.

Can someone please give me a hint what causes this behaviour?

Is there some kind of protection that the debugger disables?

Thanks,

Markus

[markus1]

I figured out, that the ECC module causes the error.

Anyway, I could not figure out how to disable it for reading the reset data without getting an ECC fault.

[dianabatrlova · Accepted solution]

Hi Markus,

I would like to recommend the proper way to retain data in the RAM after reset, please refer to the section "31.3.4 SRAM retention: power modes and resets" in the RM rev. 9.

Or you can look at the simple example for the S32K144 https://community.nxp.com/docs/DOC-342503 

I hope it helps you. 

Best Regards,

Diana