Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Renesas Electronics/R7FA4M1AB/FCACHE/FCACHEE#0x0
FCACHEEN=0
Flash Cache Enable Register
FCACHE Enable
0 (0): FCACHE is disabled
1 (1): FCACHE is enabled
These bits are read as 000000000000000. The write value should be 000000000000000.
https://github.com/cmsis-svd/cmsis-svd-data