Before the external debugger can connect to an access port, the debugger must first request the device to power up through CxxxPWRUPREQ in the SWJ-DP.
The device remains in Debug Interface mode when the debugger requests power through CxxxPWRUPREQ. Otherwise, the device is in normal mode. When a debug session is over, the device must be set to normal mode by the external debugger, followed by a pin reset. This reduces overall power consumption.
Some peripherals behave differently in Debug Interface mode compared to normal mode. These differences are described in more detail in the corresponding peripheral chapter.
For details on how to use the debug capabilities, read the debug documentation of your IDE.
If the device is in System OFF when power is requested from CxxxPWRUPREQ, the system wakes up and the DIF flag in RESETREAS is set.