Access to K82 MMCAU in UserMode

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Access to K82 MMCAU in UserMode

Senior Contributor I

Hi !

K82 have PPB bus with esome contol registers and MMCAU.


Private peripheral (PPB) bus The PPB provides access to these modules: • ARM modules such as the NVIC, ETM, ITM, DWT, FBP, and ROM table • Freescale Miscellaneous Control Module (MCM) • Memory-Mapped Cryptographic Acceleration Unit (MMCAU)


I have configured MPU where access to MMCAU is enabled in UserMode,

e,g whole peripheral area  0x40000000 - 0xFFFFFFFF have RW rights.

But any read access to MMCAU range 0xE0081000 - ...1FFFF generate BusFault.

AIPS is also dosn't have any register for enable access to MMCAU.

How I can configure K82 blocks for have access to MMCAU address rang in UserMode ?



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NXP TechSupport
NXP TechSupport

Hi Eugene,

MPU does not cover PPB(from 0xe0000000). Unprivileged access to the PPB causes BusFault errors unless otherwise stated. Notable exceptions are:

• Unprivileged accesses can be enabled to the Software Trigger Interrupt Register in the System Control Space by programming a control bit in the Configuration Control Register.
• For debug related resources.

Please download DDI0403D_arm_architecture_v7m_reference_manual.pdf from ARM website and check it at B3-707.


So your report is not a bug of ARM cortex-M4 or program error. It is just a feature of CORTEX-M4.




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