MC9S12XDP512 Secure Mode Issue

[okan_saglam]

Hello,

I am trying to use MC9S12XDP512 microcontroller in secure mode. The application code runs without any issues in unsecure mode, but when secure mode is enabled, I encounter a problem.

Based on my observations, the issue occurs when accessing variables in the SRAM region. These variables are located in the 0x20_0000–0x3F_FFFF (CS1) area. When secure mode is active, the program unexpectedly stops running.

Is there any special configuration required for SRAM access in secure mode?
Do you have any suggestions?

Best regards.

[lama]

Hi,

It does not smell me like security issue but something between debug and normal mode together with writing mode register twice (it is write once only in the normal mode).

BTW, do not you mix security and protection?

https://community.nxp.com/t5/S12-MagniV-Microcontrollers/S12XD-S12XE-External-BUS-design-Addendum-To...

Please read AN-ExBUS-AddendumToAN2708-v.0.2.zip chapter 5.2 SW Solution from the page and compare design.

I believe you will find the source of the issue because I do not see into your HW and SW design.

Best regards,

Ladislav