Wakeup DA14531 from Deep Sleep using RTC, Clocked wakeup controller

Question

We are using DA14531MOD with SDK 6.0.14.1114. We are using RTC alarm & clocked wakeup controller(P0_11) in deep sleep mode using below code 
 rtc_get_time_clndr( &time, NULL ); // Alarm interrupt in five seconds alarm_time = time; alarm_time.sec += 10; rtc_set_alarm( &alarm_time, NULL, RTC_ALARM_EN_SEC ); 
 wkupct_enable_irq(WKUPCT_PIN_SELECT(GPIO_BUTTON_PORT, GPIO_BUTTON_PIN), // Select pin WKUPCT_PIN_POLARITY(GPIO_BUTTON_PORT, GPIO_BUTTON_PIN, WKUPCT_PIN_POLARITY_LOW), // Polarity low 1, // 1 event 0); // debouncing time = 0 
 // Ensure PD_TIM is open SetBits16(PMU_CTRL_REG, TIM_SLEEP, 0); 
 // Wait until PD_TIM is opened while ((GetWord16(SYS_STAT_REG) & TIM_IS_UP) != TIM_IS_UP); 
 // Go to deep sleep arch_set_deep_sleep(PD_SYS_DOWN_RAM_OFF,PD_SYS_DOWN_RAM_OFF,PD_SYS_DOWN_RAM_OFF, false ); 
 No issue is found to Wakeup the device from above sources. We are expecting RTC date & time should not reset after wakeup from sleep. 
 returns always zero with GetBits16(SYS_STAT_REG, TIM_IS_UP); after wake up 
 Issues we are facing here 1. RTC date & time is not continuing after wake up. 2. After wakeup from sleep from any one source, How to find out from which source (either RTC alarm, clocked) the DA14531 wakeups.

JH_Renesas · Answer

1, have you called this function rtc_set_keep_reg_on_reset 
 void rtc_init(const rtc_config_t *cfg)
{
 rtc_set_hour_clk_mode(cfg->hour_clk_mode);
 // this keep_rtc should be true, when you want keep rtc registors
 rtc_set_keep_reg_on_reset(cfg->keep_rtc);
} 
 2, there is no register for wake up source, so you can distinguish the callbacks for different sources. 
 DA14531 deep sleep - multiple wake up events possible? - Bluetooth Low Energy - Wireless Connectivity - Renesas Engineering Community

JH_Renesas · Answer

Hi Vijay, 
 Let's make a conclusion. 
 1, RTC can be alive during sleep as we talked using 
 // Ensure PD_TIM is open SetBits16(PMU_CTRL_REG, TIM_SLEEP, 0); 
 So, you can wake up by the RTC. 
 2, RTC can retain the registers during SW reset by using this API: 
 // this keep_rtc should be true, when you want keep rtc registors rtc_set_keep_reg_on_reset(cfg->keep_rtc); 
 This means when software reset triggered, the RTC registers can be retained. 
 But the wake-up belongs to HW/POR reset, so we can not avoid re configuration of the RTC. 
 So, the RTC can works as a wake-up source but can't keep it's data after wake-up. you need align the current time after initialized by BLE service or other sources. 
 BR, 
 JH_Renesas