[willis936]

And there is ECC in every level of cache in every CPU and often on main memory. TMR is for radiation environments unsafe for humans.

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Not sure if I understood your comment correctly, but there is certainly not ECC in every CPU and main memory. The majority of RAM sticks you can buy do not support ECC. The NXP i.MX 8 application processors and Raspberry Pis that I was using do not support ECC memory. Also, all Cortex-M MCUs older than Cortex-M7 have no ECC in the core, and even with Cortex-M7 it is an optional extension used by STM32H7 but not NXP i.MX RT1160, 1060, 1050, etc