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LPC43xx Deep power down wakeup after more than 64seconds

Question asked by Kha Vo on Dec 8, 2016
Latest reply on Dec 10, 2016 by Kha Vo

Hi all,

As LPCOpen sample pmc_states.c,

        Chip_ATIMER_DeInit(LPC_ATIMER);
        ATIMER_ClearInts();
        Chip_ATIMER_Init(LPC_ATIMER, RTC_ALARM_TIME*1000);
        LPC_ATIMER->DOWNCOUNTER = RTC_ALARM_TIME*1000;
        Chip_ATIMER_IntEnable(LPC_ATIMER);
                
        /* Call Pre SleepPowerDown function */
        PMC_Pre_SleepPowerDown();

        /* Goto Deep Sleep mode */
        Chip_PMC_Set_PwrState(Pwr_state);

MCU will wake-up by ATimer, but this is Timer 16bit and runs at 1024Hz clock, so the maximum time is 64 second.

1. How could sleep more than that?
2. Is RTC wake-up really work? If it is, why we need to config the ATimer?


Thanks in advance!


Regards,
Kha Vo

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