This post describes the Cache.
MCU cache is a function that stores addresses and Read/Write values (variables, constants, MCU function registers, and instruction codes) accessed by the CPU in cache memory in order to shorten the access time to CPU variables, constants, instruction codes, and MCU function registers. When the address is accessed, the value in the cache memory is returned to the CPU.
Points to note for cache
Depending on the MCU, if the RAM value is rewritten using DMA, etc. without going through the CPU, it is not stored in the cache memory, so a value different from the RAM value may be read out. please check the MCU manual carefully.