The devices are full static CMOS devices. Three low-power modes are provided:
|IDLE:||Place CPU in low-power mode. Peripheral clocks may be turned off selectively and only those peripherals that must function during IDLE are left operating. An enabled interrupt from an active peripheral or the watchdog timer will wake the processor from IDLE mode.|
|STANDBY:||Turns off clock to CPU and peripherals. This mode leaves the oscillator and PLL functional. An external interrupt event will wake the processor and the peripherals. Execution begins on the next valid cycle after detection of the interrupt event|
|HALT:||This mode basically shuts down the device and places it in the lowest possible power consumption mode. If the internal zero-pin oscillators are used as the clock source, the HALT mode turns them off, by default. To keep these oscillators from shutting down, the INTOSCnHALTI bits in CLKCTL register may be used. The zero-pin oscillators may thus be used to clock the CPU watchdog in this mode. If the on-chip crystal oscillator is used as the clock source, it is shut down in this mode. A reset or an external signal (through a GPIO pin) or the CPU watchdog can wake the device from this mode.|
The CPU clock (OSCCLK) and WDCLK should be from the same clock source before attempting to put the device into HALT or STANDBY.