Application Interrupt and Reset Control Register behaviour

I'm using a STM32F401RE.

I'm trying to perform a Reset using the Application Interrupt and Reset Control Register

https://developer.arm.com/documentation/dui0497/a/cortex-m0-peripherals/system-control-block/application-interrupt-and-reset-control-register

This register is at address 0xE000ED0C and bit [2] controls the reset [2]SYSRESETREQ set 1 = requests a system level reset.

When I set this bit to 1 no reset takes place and the program continues to the next statement.

Any ideas? thanks