How to Lock MPU_NS Settings?

Question

Hi, 
 
 For Renesas MCUs with TrustZone-M, if it is possible to lock the non-secure MPU (i.e., MPU_NS) configurations? This feature is supported by several ST MCUs such as STM32L552ZE. 
 Thanks!

AZ_Renesas · Accepted Answer

Arm MPU registers are defined by Arm and are not described on the RA hardware manual. 
 
 For more information and for how they are protected please check the following documents: 
 Arm&reg; Cortex&reg;-M33 Processor Technical Reference Manual

Armv8-M Architecture Reference Manual

AZ_Renesas · Answer

Hello, 
 On Cortex-M33 devices (like RA4M2) which support Trustzone, MMPUSARx registers are write-protected by PRCR.PRC4 bit:

Also registers related to the Bus Master MPU are protected by the PROTECT bit:

I hope this answers your question.

How to Lock MPU_NS Settings?

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