STM32L051C8 Current Consumption Test

stm32l051-lpwr-test.c

#include "stm32l0xx.h"

/*
 * Stop mode/LSE/RTC: 1.28uA
 * Stop mode without RTC: 0.4uA
**/
//#define RTC_ENABLE

int main(void)
{
	/**  */
	RCC->APB1ENR |= (RCC_APB1ENR_PWREN);
	PWR->CR = (PWR->CR & ~(PWR_CR_VOS)) | PWR_CR_VOS_0;
	while(PWR->CSR & PWR_CSR_VOSF);

	/** DBP enable */
    	PWR->CR |= PWR_CR_DBP;

	/* Disable PWR clock */
	RCC->APB1ENR &= (uint32_t)(~RCC_APB1ENR_PWREN);

	/* Enable HSI, wait until ready */
	RCC->CR |= RCC_CR_HSION | RCC_CR_HSIDIVEN;
	while ((RCC->CR & (RCC_CR_HSIRDY |RCC_CR_HSIDIVF)) != (RCC_CR_HSIRDY |RCC_CR_HSIDIVF));

	/* Enable PLL, set HSI as PLL source, wait until PLL is ready */
	RCC->CFGR |= RCC_CFGR_PLLSRC_HSI | RCC_CFGR_PLLMUL8 | RCC_CFGR_PLLDIV2;
	RCC->CR |= RCC_CR_PLLON;
	while ((RCC->CR & RCC_CR_PLLRDY)  == 0);

	/* Choose PLL as System clock */
	RCC->CFGR |= RCC_CFGR_SW_PLL;
	while ((RCC->CFGR & RCC_CFGR_SWS_PLL)  == 0);

	/* Enable all GPIO clock */
	RCC->IOPENR |= RCC_IOPENR_GPIOAEN | RCC_IOPENR_GPIOBEN | RCC_IOPENR_GPIOCEN | \
		RCC_IOPENR_GPIODEN | RCC_IOPENR_GPIOHEN;

	/* Take care of PA4, set to Analog input */
	// PA4 is set as input by default, this cause current leakage(~4uA)
	GPIOA->MODER |= (0x03 << 4*2);

	/* Disable GPIO clock for stop mode */
	RCC->IOPENR &= (uint32_t)~(RCC_IOPENR_GPIOAEN | RCC_IOPENR_GPIOBEN | RCC_IOPENR_GPIOCEN | \
		RCC_IOPENR_GPIODEN | RCC_IOPENR_GPIOHEN);

#ifdef RTC_ENABLE

	/** reset RTC */
	RCC->CSR |= RCC_CSR_RTCRST;
	RCC->CSR &= ~RCC_CSR_RTCRST;

	/** enable LSE */
	RCC->CSR |= RCC_CSR_LSEON;
	while((RCC->CSR & RCC_CSR_LSERDY)!=RCC_CSR_LSERDY);

	/** Enable RTC, use LSE as clock */
    	RCC->CSR = (RCC->CSR & ~RCC_CSR_RTCSEL) | RCC_CSR_RTCEN | RCC_CSR_RTCSEL_0;

	/* Enable Alarm interrupt */
	RTC->WPR = 0xCA;
	RTC->WPR = 0x53;
	RTC->CR &=~ RTC_CR_ALRAE;
	while((RTC->ISR & RTC_ISR_ALRAWF) != RTC_ISR_ALRAWF)
	{
	/* add time out here for a robust application */
	}
	RTC->ALRMAR = 0;
	RTC->CR = RTC_CR_ALRAIE | RTC_CR_ALRAE;
	RTC->WPR = 0xFE;
	RTC->WPR = 0x64;

	/**  */
	EXTI->IMR |= EXTI_IMR_IM17;
	EXTI->RTSR |= EXTI_RTSR_TR17;
	NVIC_SetPriority(RTC_IRQn, 0);
	NVIC_EnableIRQ(RTC_IRQn);

	RTC->WPR = 0xCA;
	RTC->WPR = 0x53;
	RTC->ISR |= RTC_ISR_INIT;
	while((RTC->ISR & RTC_ISR_INITF)!=RTC_ISR_INITF)
	{
	/* add time out here for a robust application */
	}
	RTC->PRER = 0x00010001;
	RTC->TR = 0; /* (5) */
	RTC->DR = 0x00002101;
	RTC->CR = (RTC->CR & ~RTC_CR_FMT);
	RTC->ISR &=~ RTC_ISR_INIT;
	RTC->WPR = 0xFE;
	RTC->WPR = 0x64;

#endif

	while (1) /* Infinite loop */
	{
		/* Set SLEEPDEEP bit of Cortex System Control Register */
		SCB->SCR |= SCB_SCR_SLEEPDEEP_Msk;

		/* Enable PWR clock */
		RCC->APB1ENR |= RCC_APB1ENR_PWREN;

		/* Disable the Power Voltage Detector */
		PWR->CR &= (uint32_t)(~PWR_CR_PVDE);
		PWR->CR = ( PWR->CR & (uint32_t)(~PWR_CR_PLS) )| PWR_CR_PLS_LEV4;

		/* Set MCU in ULP (Ultra Low Power) */
		PWR->CR |= PWR_CR_ULP;

		/*Enable fast wakeUp*/
		PWR->CR |= (uint32_t)(PWR_CR_FWU);

		/* Enter Stop mode(not standby mode) when mcu enters deepsleep */
		PWR->CR &= (uint32_t)(~PWR_CR_PDDS);

		/* Regulator is in low power mode */
		PWR->CR |= PWR_CR_LPSDSR;

		/* WeakUp flag must be cleared before enter sleep again */
		PWR->CR |= (uint32_t)(PWR_CR_CWUF);
		while( (PWR->CSR & PWR_CSR_WUF) == PWR_CSR_WUF );

		/* Disable PWR clock */
		RCC->APB1ENR &= (uint32_t)(~RCC_APB1ENR_PWREN);

		__WFI();
	}
}