16.6.2.7 Reset Controller

The latest reset cause is available in RCAUSE, and can be read during the application boot sequence in order to determine proper action.

There are two groups of reset sources:

  • Power Reset: Resets caused by an electrical issue.
  • User Reset: Resets caused by the application.

The table below lists the parts of the device that are reset, depending on the reset type.

Table 16-2. Effects of the Different Reset Events
Power ResetUser Reset
POR, BOD12, BOD33External ResetWDT Reset, SysResetReq
RTC
All the 32kHz sources
WDT with ALWAYSON feature
Generic Clock with WRTLOCK featureYNN
Debug logicYYN
OthersYYY

The external reset is generated when pulling the RESET pin low. This pin has an internal pull-up, and does not need to be driven externally during normal operation.

The POR, BOD12 and BOD33 reset sources are generated by their corresponding module in the System Controller Interface (SYSCTRL).

The WDT reset is generated by the Watchdog Timer.

The System Reset Request (SysResetReq) is a software reset generated by the CPU when asserting the SYSRESETREQ bit located in the Reset Control register of the CPU (See the ARM® Cortex® Technical Reference Manual on http://www.arm.com).

Figure 16-3. Reset Controller