Daniel kalu
DIIDevHeads IoT Integration Server
•Created by Daniel kalu on 6/14/2024 in #middleware-and-os
What exactly do inner and outer cache policies refer to?
Hey guys @Middleware & OS I am trying to develop my own RTOS kernel for a Cortex-M7 STM32F746 Disco board and setting memory access policies using the MPU. I need to understand the difference between inner and outer cache policies. According to ARM documentation, the inner policy affects caches inside the processor, while the outer policy signals on the memory bus for external caching systems. Could someone clarify:
1. What exactly do inner and outer cache policies refer to?
2. How do these policies apply to internal SRAM vs. external SDRAM, especially if there's no external L2 cache?
3. Does the outer policy matter when configuring internal SRAM?
I'm familiar with general cache concepts, but the documentation is unclear on inner vs. outer policies.
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