SYSCFG Cortex-M55 control register
| FPU_IT_EN | Enable FPU exception |
| LOCKSVTAIRCR | Prevent changes to: |
| LOCKNSVTOR | Prevent changes to the non-secure vector table base address. |
| LOCKSMPU | Prevent changes to programmed secure MPU memory regions. |
| LOCKNSMPU | Prevent changes to non-secure MPU memory regions already programmed. |
| LOCKSAU | Prevent changes to secure SAU memory regions already programmed. |
| LOCKDCAIC | Disable access to the instruction cache direct cache access registers DCAICLR and DCAICRR. |