MM32 RTC学习(兼容STM32)

RTC学习

RTC简述

思维导图

RTC框图

RTC电源框图(详细请看电源控制(PWM)章节)

认识理解

配置简单RTC(寄存器版)(注意修改头文件)

#include "all.h"

void delay(uint32_t num)

{

    uint32_t i;

    for(i=0;i<num;i++);

}

void rtc_work_cfg()

{

    uint32_t    scaler;

    uint32_t    cnt;

    RCC->APB1ENR |= 1<<28;   //Enable the PWREN clock.

    RCC->APB1ENR |= 1<<27;   //Enable the PWREN clock.

    PWR->CR |= 1<<8;         //Enable access to the RTC and backup registers.

    RCC->BDCR |= 1<<16;    //Force the Backup domain reset.

    RCC->BDCR &= ~(1<<16); //Release the Backup domain reset.

    RCC->BDCR |= 1<<15;    //Enable RTC clock.

    RCC->BDCR |= 1<<8;     //select LES as RTC clock source.

    RCC->BDCR |= 1<<0;     //External low-speed oscillar enable.

    while(!(RCC->BDCR & 0x1<<1));  //External low-speed clock ready flag.

    while(!(RTC->CRL & 1<<5)); //Wait until last write operation on RTC registers has finished.

    RTC->CRL |= 1<<4;     //Enter the RTC configuration mode.

    RTC->ALRH = 0x0;      //Set the RTC alarm value.

    RTC->ALRL = 0x300;

    RTC->PRLH = 0x0;      //Set the RTC prescaler value.

    RTC->PRLL = 0x10;

    RTC->CNTH = 0x0;      //Set the RTC counter value.

    RTC->CNTL = 0x50;

    RTC->CRL &= ~(1<<4);  //Exit from the RTC configuration mode.

    while(!(RTC->CRL & 1<<5));  //Wait until last write operation on RTC registers has finished.

    while(!(RTC->CRL & 1<<3));  //wait until the RTC registers (RTC_CNT, RTC_ALR and RTC_PRL) are synchronized with RTC APB clock.

    delay(1000);

    cnt  = RTC->CNTL;

    cnt |= RTC->CNTH << 16;

    scaler  = RTC->PRLL;

    scaler |= RTC->PRLH << 16;

    delay(100);

    printf_info("Prescaler = %x,cnt = %x\n",scaler,cnt);

}

void main()

{

    rtc_work_cfg();

}

配置简单RTC(库函数版)(注意修改头文件)

#include "all.h"

void delay(uint32_t num)

{

    uint32_t i;

    for(i=0;i<num;i++);

}

void rtc_work_cfg()

{

    uint32_t    scaler;

    uint32_t    cnt;

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR,ENABLE);

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_BKP,ENABLE);

    PWR_BackupAccessCmd(ENABLE);  // Enable or disables access to the RTC and backup registers.

    RCC_BackupResetCmd(ENABLE);

    RCC_BackupResetCmd(DISABLE);

    RCC_RTCCLKCmd(ENABLE);        //Enable or disables the RTC clock.

    RCC_RTCCLKConfig(RCC_RTCCLKSource_LSE); //Configure the RTC clock (RTCCLK).

    RCC_LSEConfig(RCC_LSE_ON);    //Configure the External Low Speed oscillator (LSE).

    while(!(RCC->BDCR & 0x1<<1)); // //External low-speed clock ready flag.

    RTC_WaitForLastTask();   //Wait until last write operation on RTC registers has finished.

    RTC_EnterConfigMode();   //Enter the RTC configuration mode.

    RTC_SetPrescaler(0x80);  //Set the RTC prescaler value.

    RTC_SetCounter(0x50);    //Set the RTC counter value.

    RTC_SetAlarm(0x150);     //Set the RTC alarm value.

    RTC_ExitConfigMode();     //Exit from the RTC configuration mode.

    RTC_WaitForLastTask();   //Wait until last write operation on RTC registers has finished.

    RTC_WaitForSynchro();    //wait until the RTC registers (RTC_CNT, RTC_ALR and RTC_PRL) are synchronized with RTC APB clock.

    delay(8000);

//***************************************************

    RTC_WaitForLastTask();   //Wait until last write operation on RTC registers has finished.

    RTC_EnterConfigMode();   //Enter the RTC configuration mode.

    RTC_SetCounter(0x500);   //Set the RTC counter value.

    RTC_ExitConfigMode();    //Exit from the RTC configuration mode.

    RTC_WaitForLastTask();   //Wait until last write operation on RTC registers has finished.

    RTC_WaitForSynchro();    //wait until the RTC registers (RTC_CNT, RTC_ALR and RTC_PRL) are synchronized with RTC APB clock.

//***************************************************

    delay(8000);

    cnt = RTC_GetCounter();

    scaler = RTC_GetDivider();

    delay(100);

    printf_info("Prescaler = %x,cnt = %x\n",scaler,cnt);

}

void main()

{

    rtc_work_cfg();

}

参考资料

[1]. MM32 miniboard资料