Datasheet

LPC540xx All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2018. All rights reserved.
Product data sheet Rev. 1.8 — 22 June 2018 67 of 168
NXP Semiconductors
LPC540xx
32-bit ARM Cortex-M4 microcontroller
Table 9 shows wake-up sources for reduced power modes.
Table 9. Wake-up sources for reduced power modes
Power mode Wake-up source Conditions
Sleep Any interrupt Enable interrupt in NVIC.
HWWAKE Certain Flexcomm Interface and DMIC subsystem activity.
Deep-sleep Pin interrupts Enable pin interrupts in NVIC and STARTER0 and/or STARTER1 registers.
BOD interrupt
• Enable interrupt in NVIC and STARTER0 registers.
• Enable interrupt in BODCTRL register.
• Configure the BOD to keep running in this mode with the power API.
BOD reset Enable reset in BODCTRL register.
Watchdog interrupt
• Enable the watchdog oscillator in the PDRUNCFG0 register.
• Enable the watchdog interrupt in NVIC and STARTER0 registers.
• Enable the watchdog in the WWDT MOD register and feed.
• Enable interrupt in WWDT MOD register.
• Configure the WDTOSC to keep running in this mode with the power API.
Watchdog reset
• Enable the watchdog oscillator in the PDRUNCFG0 register.
• Enable the watchdog and watchdog reset in the WWDT MOD register and feed.
Reset pin Always available.
RTC 1 Hz alarm timer
• Enable the RTC 1 Hz oscillator in the RTCOSCCTRL register.
• Enable the RTC bus clock in the AHBCLKCTRL0 register.
• Start RTC alarm timer by writing a time-out value to the RTC COUNT register.
• Enable the RTCALARM interrupt in the STARTER0 register.
RTC 1 kHz timer
time-out and alarm
• Enable the RTC 1 Hz oscillator and the RTC 1 kHz oscillator in the RTC CTRL
register.
• Start RTC 1 kHz timer by writing a value to the WAKE register of the RTC.
• Enable the RTC wake-up interrupt in the STARTER0 register.
Micro-tick timer
(intended for ultra-low
power wake-up from
deep-sleep mode
• Enable the watchdog oscillator in the PDRUNCFG0 register.
• Enable the Micro-tick timer clock by writing to the AHBCLKCTRL1 register.
• Start the Micro-tick timer by writing UTICK CTRL register.
• Enable the Micro-tick timer interrupt in the STARTER0 register.
I2C interrupt Interrupt from I2C in slave mode.
SPI interrupt Interrupt from SPI in slave mode.
USART interrupt Interrupt from USART in slave or 32 kHz mode.
USB0 need clock
interrupt
Interrupt from USB0 when activity is detected that requires a clock.
USB1 need clock
interrupt
Interrupt from USB1 when activity is detected that requires a clock.
Ethernet interrupt Interrupt from ethernet.
DMA interrupt Interrupt from DMA.
HWWAKE Certain Flexcomm Interface and DMIC subsystem activity.