Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Atmel/ATSAM4S4B/EFC0/FMR#0x0
EEFC Flash Mode Register
Flash Ready Interrupt Enable
Flash Wait State
Sequential Code Optimization Disable
Flash Access Mode
Code Loop Optimization Enable
https://github.com/cmsis-svd/cmsis-svd-data