Non-cached memory

Michael Fowler 131 Reputation points
2022-08-30T15:43:41.613+00:00

In the example code that came with my iMXRT1050, many variable associated with ThreadX are in non-cacheable memory. Some things in the non-cacheable ram are the IP packet pool and the USB memory area. Is it necessary to have those non-cached? More broadly, when is non-cached required by ThreadX?

Azure RTOS
Azure RTOS
An Azure embedded development suite including a small but powerful operating system for resource-constrained devices.
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  1. Scott Azure RTOS 4,051 Reputation points
    2022-08-31T16:23:31.183+00:00

    Hi @Michael Fowler

    Both ethernet packets and USB memory need to be in non-cached memory. Here's a great link that provides some good explanations as to why: https://stackoverflow.com/questions/90204/why-would-a-region-of-memory-be-marked-non-cached

    GUIX frame buffers also need to be in non-cached memory.

    1 person found this answer helpful.