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> data to be stored within the CPU I don’t know anything about CPU design. Am I wrong to read this line and be worried about memory access vulnerabilities like
by teej 6y ago
> data to be stored within the CPU
I don’t know anything about CPU design. Am I wrong to read this line and be worried about memory access vulnerabilities like have been found with Intel CPUs?
- formerly_proven 6y agoTightly coupled memory is basically a cache, except it's explicitly mapped at an address. In MCUs it's faster and also more "secure" in a sense, because, just like a cache, you can't DMA into TCM, so peripherals can't write garbage or shellcode into TCM. The upside of TCM over a cache is that it doesn't need the quick logic to for cache lookups and the storage for tags (so smaller, lower power than a cache), while the downside - it being explicit - is less of a problem and sometimes an advantage in embedded systems.
- teej 6y agoI understand a lot better now, thanks!
- rbanffy 6y agoLocal memory can also be handy in general-purpose computing - there's always some data that belongs to a given core that doesn't need to be consistent across shared memory.
- easde 6y agoMany MCUs / SoCs support DMA into tightly coupled memories. Very useful for "ping-pong buffering" to hide memory copying overhead - copying one buffer into a TCM bank while the processor works on a different TCM bank.