Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32h7rs/STM32H7R/DBGMCU/DBGMCU_CIDR1#0x0
PREAMBLE=B_0x0
DBGMCU component identity register
Component ID field, bits [11:8]
0 (B_0x0): Common ID value
Component ID field, bits [15:12] - component class
15 (B_0xF): System component with non-standard register layout
https://github.com/modm-io/cmsis-svd-stm32