There are 4 main power reduction modes in the LPC1700 family: Sleep, Deep-Sleep, Power-Down, and Deep Power-Down. Sleep Mode on the LPC17xx corresponds to the Idle mode on LPC2xxx series devices. The name has changed because ARM has incorporated portions of reduced power mode control into the Cortex-M3. In this mode, CPU execution is suspended and peripherals continue to run. In Sleep-Mode, execution of instructions is suspended until either a reset or an interrupt occurs. Peripheral functions continue operation during Sleep-Mode and may generate interrupts to cause the processor to resume execution. A wake up from Sleep mode will occur whenever any enabled interrupt occurs. Deep-Sleep mode on the LPC17xx corresponds to the Sleep Mode on LPC23xx and LPC24xx series devices. When the chip enters the Deep-Sleep Mode, the main oscillator is powered down, nearly all clocks are stopped. The IRC remains running and can be configured to drive the Watchdog Timer, allowing the Watchdog to wake up the CPU. The 32kHz RTC oscillator is not stopped and RTC interrupts may be used as a wakeup source. The flash is left in the standby mode allowing a quick wakeup. The PLLs are automatically turned off and disconnected. The CCLK and USBCLK clock dividers automatically get reset to zero. The processor state and registers, peripheral registers, and internal SRAM values are preserved throughout Deep Sleep mode and the logic levels of chip pins remain static. The Deep-Sleep mode can be terminated and normal operation resumed by either a Reset or certain specific interrupts that are able to function without clocks.