MPU Configuration

Hello Team,

I am working on ARM Cortex-M3 processor based MCU and I would like to separate the software on different section based on MPU configuration.

So I understand region configuration and MPU configuration but I don't understand Access Permission. (Priviliged and Unprivileged). Moreover, I wanted to know about read only and R/W memory protection.

For example: If I configure the region 0 (flash memory) as read only, would it be possible to change R/W for region 0 after sometime or would it be only one time process?\

is there any tool available for MPU configuration?

Kindly let me know if any reference document  available.

  • Hope below lines helps a little bit.

    #1. Access Permission. (Priviliged and Unprivileged): usually, modern CPUs can works in different mode (User mode , system mode for example; usually user mode for application, and system mode for OS; For M3, naming may differ but things are similar). MPU can help to setup different access permission for Priviliged and Unprivileged (ie. app/OS) for regions. 

    #2. MPU configuring is not one-time process, you can change them on-the-fly but you shall follow the correct flow.