7.2.1. Using memory types

All of the processor interfaces to the external memory system have associated store buffers that help to improve the throughput of accesses to Normal type memory. See Store buffer and Peripheral interfaces for more information. Because of the ordering rules that they must follow, accesses to other types of memory typically have a lower throughput or higher latency than accesses to Normal memory. In particular:

Similarly, when it is accessing Strongly Ordered or Device type memory, the processor's response to interrupts must be modified, and the interrupt response latency is longer. See Low interrupt latency for more information.

To ensure optimum performance, you must understand the architectural semantics of the different memory types. Use Device memory type for appropriate memory regions, typically peripherals, and only use Strongly Ordered memory type for memory regions where it is essential.

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