External Private Peripheral Bus


What is exact differences between IPPB (Internal Private Peripheral Bus) and EPPB (External Private Peripheral Bus)?

I think that IPPB peripherals and components are inside the processor (Cortex-M3/M4 core etc.) but, the EPPB peripherals and components are outside the processor and in microcontroller, like Memories and peripherals that microcontroller vendor adds them to  its own products and are different from other microcontroller vendor.

Is this comparison between IPPB and EPPB correct? If it's not, please help me to understand  this issue clearly.


  • IPPB is inside of processor and has been used to integrate with internal CoreSight components. The External PPB (EPPB) space, 0xE0040000 up to 0xE0100000, is intended for CoreSight-compatible debug and trace components, and has a number of irregular limitations which make it less useful for regular system peripherals. Arm does not recommend to integrate other components besides of CoreSight components.

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