Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/STMicroelectronics/STM32F427/DBG/DBGMCU_CR#0x0
Control Register
DBG_SLEEP
DBG_STOP
DBG_STANDBY
TRACE_IOEN
TRACE_MODE
https://github.com/cmsis-svd/cmsis-svd-data