Cortex-A is not a microcontroller core. It's an application CPU, and very commonly code is ran out of DRAM (with large random-access latency). Does not relate to microcontrollers; so completely apples-to-oranges comparison. One of the defining factors of what microcontroller is, is the ability of timing critical control with low latency and low jitter, compared to application CPUs. Hence simplicity and lack of caches, or in more complex MCUs like Cortex-M7, addition of core-coupled memories.
Now I understand completely where your strawman is coming from. You mix application CPUs and microcontrollers up.
I'm not "attacking" ad hominem. I'm truly suspecting based on your behavior, and I think with good reasons. I might be wrong, though, in which case I'm sorry. On the other hand, I hope I'm right, because your continued mispresentation of facts, which seems to be on purpose, is detrimental to the discussion. I hope it at least does good on your wallet, then there would be at least one winner in this stupid reoccurring game - yourself.
Interestingly, you reply to threads that talk about "MCU"s, write "MCU" yourself, but somehow, suddenly, it has been changed to "conventional processors".
Nobody outside of your strawman is using Pentium or Cortex-A9 for nearly cycle-accurate hard realtime applications, or ever suggested doing that. We use microcontrollers, such as Cortex-M7. Caches do not affect the ISR jitter, because ISRs where this matters are not in cacheable (slow) memory. This is a fact.
I want to call BS out in a well-mannered way, but continued ignorance of the arguments for years leads to certain conclusions being made. You are supplying the same completely wrong information repeatedly, and it seems this behavior can't be corrected by rational argumentation (i.e., supplying the correct information), which has been attempted by me and many others, time after time. You continue to present the same old strawman, made up by calling not-a-microcontroller a microcontroller, and pretending this strawman has any relevance to real life.