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.
3 Replies
No worries @Daniel kalu inner or outer cache policies are for multi-level caching
You have to rather focus on the inner policy for your setup.
@Daniel kalu go thru this context about inner policies and outer policies and their relevance for internal SRAM and external SDRAM
