Confusion about external flash: should be configured as cacheable or non-cacheable ?

[ranran]

Hello,

I am a bit confused with how to declare external nor flash (FMC) through MPU.

I am using the external flash as following:

1. program the application into the external flash
2. bootloader starts in intrernal flash, and then run the application from external flash

With eval (stm32h743) I (think) I configured flash as non cacheable and it worked fine, but seems like in custom board 9with different flash), it should be configured as cacheable.

So, how should it be actually configured: chaceable or not-cacheable ?

And if cacheable, how do I assure that programming is correct into flash ?

Thank you,

ranran

[Tesla DeLorean]

The magic sequences used by NOR are problematic as they contaminate the cache with data not actually written into the memory space. NAND is a block storage method, again data written may be different from that currently visible, and data currently visible changes.