Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32u5/STM32U5Fx/GTZC1_MPCBB6/MPCBB6_CR#0x0
MPCBB control register
lock the control register of the MPCBB until next reset
SRAMx clocks security state
secure read/write illegal access disable
https://github.com/modm-io/cmsis-svd-stm32