Product Specs

Table Of Contents
18 POWER Power supply
Page
82
18.5 RAM sections
RAM section power control is used for retention in System OFF mode and for powering down unused
sections in System ON mode.
Each RAM section can power up and down independently in both System ON and System OFF mode. See
chapter Memory on page 23 for more information on RAM sections.
18.6 Reset
There are multiple sources that may trigger a reset.
After a reset has occurred, register RESETREAS can be read to determine which source generated the
reset.
18.6.1 Power-on reset
The power-on reset generator initializes the system at power-on.
The system is held in reset state until the supply has reached the minimum operating voltage and the internal
voltage regulators have started.
A step increase in supply voltage of 300 mV or more, with rise time of 300 ms or less, within the valid supply
range, may result in a system reset.
18.6.2 Pin reset
A pin reset is generated when the physical reset pin on the device is asserted.
Pin reset is configured via the PSELRESET[0] and PSELRESET[1] registers.
Note: Pin reset is not available on all pins.
18.6.3 Wakeup from System OFF mode reset
The device is reset when it wakes up from System OFF mode.
The DAP is not reset following a wake up from System OFF mode if the device is in debug interface mode.
Refer to chapter Debug and trace on page 72 for more information.
18.6.4 Soft reset
A soft reset is generated when the SYSRESETREQ bit of the Application Interrupt and Reset Control
Register (AIRCR register) in the ARM® core is set.
Refer to ARM documentation for more details.
A soft reset can also be generated via the RESET on page 73 register in the CTRL-AP.
18.6.5 Watchdog reset
A Watchdog reset is generated when the watchdog times out.
Refer to chapter WDT Watchdog timer on page 410 for more information.
18.6.6 Brown-out reset
The brown-out reset generator puts the system in reset state if the supply voltage drops below the brownout
reset (BOR) threshold.
Refer to section Power fail comparator on page 99 for more information.