本帖最后由 L-MCU 于 2024-6-25 14:38 编辑
1、实时时钟（RTC） 关于CH32L103 RTC具体介绍，可看CH32L103应用手册。 关于RTC的预分频系数，最高可设置为2的20次方，但一般根据所用RTC时钟源设置。如LSE频率为32.768KHz，设置预分频器重装值寄存器（RTC_PSCRL）值为0x7FFF，则RTC就1s计数一次。寄存器具体介绍如下。 关于RTC的时钟源，可选为LSE或LSI或HSE128分频，如下图。一般选择LSE或LSI。 关于RTC的复位，其中预分频，预分频重装值，主计数器和闹钟，只能通过后备域的复位信号复位，而RTC控制寄存器由系统复位或电源复位控制。
2、RTC应用 CH32L103 EVT提供了RTC日历例程，程序中，使用TIM1进行RTC校准，TIM定时器设置1us计数一次，重装载值设置为65535，即65536us进一次中断，进一次更新中断计数加1。RTC秒中断中，对TIM计数器的值进行判断，理论上1s=1000000us，将TIM计数器的值与1000000进行比较，根据这之间的差值进行校准。具体的校准函数可参考RTC例程。 RTC例程配置使用LSE作为时钟源，此外还可以配置LSI或HSE/128作为时钟源，注意使用HSE/128作为时钟源时，要配置时钟控制寄存器（RCC_CTLR）使能开启HSE振荡器，可以使用HSE配置系统主频。 下代码为在RTC日历例程基础上修改的可配置使用LSI或HSE/128作为RTC时钟源，完整代码可见附件例程。 /********************************** (C) COPYRIGHT *******************************
* File Name : main.c
* Author : WCH
* Version : V1.0.0
* Date : 2024/02/21
* Description : Main program body.
*********************************************************************************
* Copyright (c) 2021 Nanjing Qinheng Microelectronics Co., Ltd.
* Attention: This software (modified or not) and binary are used for
* microcontroller manufactured by Nanjing Qinheng Microelectronics.
*******************************************************************************/
/**
* @note
* The code initializes the TIM1 timer and the RTC module, and then performs calibration on the RTC
* based on a calibration value.
*
* this code block is checking if the `CalibrationVal` is less than 1000000. If it is, it
* calculates the `FastSecPer30days` value by subtracting `CalibrationVal` from 1000000 and then
* multiplying it by the number of seconds in 30 days (3600 seconds * 24 hours * 30 days) divided
* by 1000000. This `FastSecPer30days` value is then passed to the `RTC_Calibration` function for
* further processing.
*/
#include "debug.h"
#define RTC_LSE 1
#define RTC_LSI 2
#define RTC_HSE_128 3
#define Mode RTC_HSE_128
/* Global define */
#define PPM_PER_STEP 0.9536743 // 10^6/2^20.
#define PPM_PER_SEC 0.3858025 // 10^6/(30d*24h*3600s).
/* Global Variable */
volatile uint8_t CalibrationFlag = 0;
volatile uint32_t CalibrationTIMCir = 0, CalibrationVal = 0;
typedef struct
{
vu8 hour;
vu8 min;
vu8 sec;
vu16 w_year;
vu8 w_month;
vu8 w_date;
vu8 week;
} _calendar_obj;
_calendar_obj calendar;
u8 const table_week[12] = {0, 3, 3, 6, 1, 4, 6, 2, 5, 0, 3, 5};
const u8 mon_table[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
/* Exported_Functions */
u8 RTC_Init(void);
u8 Is_Leap_Year(u16 year);
u8 RTC_Alarm_Set(u16 syear, u8 smon, u8 sday, u8 hour, u8 min, u8 sec);
u8 RTC_Get(void);
u8 RTC_Get_Week(u16 year, u8 month, u8 day);
u8 RTC_Set(u16 syear, u8 smon, u8 sday, u8 hour, u8 min, u8 sec);
volatile uint8_t Calibration_STA = 0;
void RTC_IRQHandler(void) __attribute__((interrupt("WCH-Interrupt-fast")));
void TIM1_UP_IRQHandler(void) __attribute__((interrupt("WCH-Interrupt-fast")));
/*********************************************************************
* @fn RTC_IRQHandler
*
* [url=home.php?mod=space&uid=247401]@brief[/url] This function handles RTC Handler.
*
* [url=home.php?mod=space&uid=266161]@return[/url] none
*/
void RTC_IRQHandler(void)
{
if (CalibrationFlag)
{
if (RTC_GetITStatus(RTC_IT_SEC) != RESET) /* Seconds interrupt */
{
RTC_Get();
}
if (RTC_GetITStatus(RTC_IT_ALR) != RESET) /* Alarm clock interrupt */
{
RTC_ClearITPendingBit(RTC_IT_ALR);
RTC_Get();
}
printf("year/month/day/week/hour/min/sec:\r\n");
printf("%d-%d-%d %d %d:%d:%d\r\n", calendar.w_year, calendar.w_month, calendar.w_date,
calendar.week, calendar.hour, calendar.min, calendar.sec);
}
else
{
if (RTC_GetITStatus(RTC_IT_SEC) != RESET)
{
if (Calibration_STA == 0)
{
CalibrationTIMCir = 0;
TIM1->CNT = 0;
TIM1->CTLR1 |= TIM_CEN;
Calibration_STA = 1;
}
else if (Calibration_STA == 1)
{
TIM1->CTLR1 &= ~TIM_CEN;
CalibrationVal = TIM1->CNT + CalibrationTIMCir * 65536;
CalibrationVal < 1000000 ? printf("Calibration val = %ld\n", 1000000 - CalibrationVal) : printf("Calibration val = %ld\n", CalibrationVal - 1000000);
;
TIM1->CNT = 0;
Calibration_STA = 0;
CalibrationFlag = 1;
}
}
}
RTC_ClearITPendingBit(RTC_IT_SEC | RTC_IT_OW);
RTC_WaitForLastTask();
}
void TIM1_UP_IRQHandler()
{
if (!CalibrationFlag)
CalibrationTIMCir += 1;
TIM_ClearITPendingBit(TIM1, TIM_IT_Update);
}
/*********************************************************************
* @fn TIM1_OutCompare_Init
*
* @brief Initializes TIM1 output compare.
*
* @param arr - the period value.
* psc - the prescaler value.
* ccp - the pulse value.
*
* @return none
*/
void TIM1_Base_Init(u16 arr, u16 psc)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure = {0};
NVIC_InitTypeDef NVIC_InitStructure = {0};
RCC_PB2PeriphClockCmd(RCC_PB2Periph_TIM1, ENABLE);
TIM_TimeBaseInitStructure.TIM_Period = arr;
TIM_TimeBaseInitStructure.TIM_Prescaler = psc;
TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseInitStructure);
NVIC_InitStructure.NVIC_IRQChannel = TIM1_UP_IRQn;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_Init(&NVIC_InitStructure);
TIM_ITConfig(TIM1, TIM_IT_Update, ENABLE);
TIM1->CNT = 0;
}
/*********************************************************************
* @fn RTC_NVIC_Config
*
* @brief Initializes RTC Int.
*
* @return none
*/
static void RTC_NVIC_Config(void)
{
NVIC_InitTypeDef NVIC_InitStructure = {0};
NVIC_InitStructure.NVIC_IRQChannel = RTC_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
/*********************************************************************
* @fn RTC_Init
*
* @brief Initializes RTC collection.
*
* @return 1 - Init Fail
* 0 - Init Success
*/
u8 RTC_Init(void)
{
u8 temp = 0;
RCC_PB1PeriphClockCmd(RCC_PB1Periph_PWR | RCC_PB1Periph_BKP, ENABLE);
PWR_BackupAccessCmd(ENABLE);
/* Is it the first configuration */
if (BKP_ReadBackupRegister(BKP_DR1) != 0xA1A1)//从指定的后备寄存器中读出数据:读出了与写入的指定数据不相乎
{
BKP_DeInit();
#if(Mode==RTC_LSE)
RCC_LSEConfig(RCC_LSE_ON);
while (RCC_GetFlagStatus(RCC_FLAG_LSERDY) == RESET && temp < 250)
{
temp++;
Delay_Ms(20);
}
if (temp >= 250)
return 1;
RCC_RTCCLKConfig(RCC_RTCCLKSource_LSE);
#elif(Mode==RTC_LSI)
RCC_LSICmd(ENABLE);
while (RCC_GetFlagStatus(RCC_FLAG_LSIRDY) == RESET && temp < 250)
{
temp++;
Delay_Ms(20);
}
if (temp >= 250)
return 1;
RCC_RTCCLKConfig(RCC_RTCCLKSource_LSI);
#elif(Mode==RTC_HSE_128)
RCC_RTCCLKConfig(RCC_RTCCLKSource_HSE_Div128);
#endif
RCC_RTCCLKCmd(ENABLE);
RTC_WaitForLastTask();
RTC_WaitForSynchro();
RTC_ITConfig(RTC_IT_SEC, ENABLE);
RTC_WaitForLastTask();
RTC_EnterConfigMode();
/*Deliberately speeding up the clock*/
#if(Mode==RTC_HSE_128)
RTC_SetPrescaler(62500);
#elif(Mode==RTC_LSE||Mode==RTC_LSI)
RTC_SetPrescaler(32766);
#endif
RTC_WaitForLastTask();
RTC_Set(2019, 10, 8, 13, 58, 55); /* Setup Time */
RTC_ExitConfigMode();
BKP_WriteBackupRegister(BKP_DR1, 0XA1A1);
}
else
{
RTC_WaitForSynchro(); //等待最近一次对RTC寄存器的写操作完成
RTC_ITConfig(RTC_IT_SEC, ENABLE); //使能RTC秒中断
RTC_WaitForLastTask();//等待最近一次对RTC寄存器的写操作完成
}
RTC_NVIC_Config();
RTC_Get();
return 0;
}
/*********************************************************************
* @fn Is_Leap_Year
*
* @brief Judging whether it is a leap year.
*
* @param year
*
* @return 1 - Yes
* 0 - No
*/
u8 Is_Leap_Year(u16 year)
{
if (year % 4 == 0)
{
if (year % 100 == 0)
{
if (year % 400 == 0)
return 1;
else
return 0;
}
else
return 1;
}
else
return 0;
}
/*********************************************************************
* @fn RTC_Set
*
* @brief Set Time.
*
* @param Struct of _calendar_obj
*
* @return 1 - error
* 0 - success
*/
u8 RTC_Set(u16 syear, u8 smon, u8 sday, u8 hour, u8 min, u8 sec)
{
u16 t;
u32 seccount = 0;
if (syear < 1970 || syear > 2099)
return 1;
for (t = 1970; t < syear; t++)
{
if (Is_Leap_Year(t))
seccount += 31622400;
else
seccount += 31536000;
}
smon -= 1;
for (t = 0; t < smon; t++)
{
seccount += (u32)mon_table[t] * 86400;
if (Is_Leap_Year(syear) && t == 1)
seccount += 86400;
}
seccount += (u32)(sday - 1) * 86400;
seccount += (u32)hour * 3600;
seccount += (u32)min * 60;
seccount += sec;
RCC_PB1PeriphClockCmd(RCC_PB1Periph_PWR | RCC_PB1Periph_BKP, ENABLE);
PWR_BackupAccessCmd(ENABLE);
RTC_SetCounter(seccount);
RTC_WaitForLastTask();
return 0;
}
/*********************************************************************
* @fn RTC_Alarm_Set
*
* @brief Set Alarm Time.
*
* @param Struct of _calendar_obj
*
* @return 1 - error
* 0 - success
*/
u8 RTC_Alarm_Set(u16 syear, u8 smon, u8 sday, u8 hour, u8 min, u8 sec)
{
u16 t;
u32 seccount = 0;
if (syear < 1970 || syear > 2099)
return 1;
for (t = 1970; t < syear; t++)
{
if (Is_Leap_Year(t))
seccount += 31622400;
else
seccount += 31536000;
}
smon -= 1;
for (t = 0; t < smon; t++)
{
seccount += (u32)mon_table[t] * 86400;
if (Is_Leap_Year(syear) && t == 1)
seccount += 86400;
}
seccount += (u32)(sday - 1) * 86400;
seccount += (u32)hour * 3600;
seccount += (u32)min * 60;
seccount += sec;
RCC_PB1PeriphClockCmd(RCC_PB1Periph_PWR | RCC_PB1Periph_BKP, ENABLE);
PWR_BackupAccessCmd(ENABLE);
RTC_SetAlarm(seccount);
RTC_WaitForLastTask();
return 0;
}
/*********************************************************************
* @fn RTC_Get
*
* @brief Get current time.
*
* @return 1 - error
* 0 - success
*/
u8 RTC_Get(void)
{
static u16 daycnt = 0;
u32 timecount = 0;
u32 temp = 0;
u16 temp1 = 0;
timecount = RTC_GetCounter();
temp = timecount / 86400;
if (daycnt != temp)
{
daycnt = temp;
temp1 = 1970;
while (temp >= 365)
{
if (Is_Leap_Year(temp1))
{
if (temp >= 366)
temp -= 366;
else
{
temp1++;
break;
}
}
else
temp -= 365;
temp1++;
}
calendar.w_year = temp1;
temp1 = 0;
while (temp >= 28)
{
if (Is_Leap_Year(calendar.w_year) && temp1 == 1)
{
if (temp >= 29)
temp -= 29;
else
break;
}
else
{
if (temp >= mon_table[temp1])
temp -= mon_table[temp1];
else
break;
}
temp1++;
}
calendar.w_month = temp1 + 1;
calendar.w_date = temp + 1;
}
temp = timecount % 86400;
calendar.hour = temp / 3600;
calendar.min = (temp % 3600) / 60;
calendar.sec = (temp % 3600) % 60;
calendar.week = RTC_Get_Week(calendar.w_year, calendar.w_month, calendar.w_date);
return 0;
}
/*********************************************************************
* @fn RTC_Get_Week
*
* @brief Get the current day of the week.
*
* @param year/month/day
*
* @return week
*/
u8 RTC_Get_Week(u16 year, u8 month, u8 day)
{
u16 temp2;
u8 yearH, yearL;
yearH = year / 100;
yearL = year % 100;
if (yearH > 19)
yearL += 100;
temp2 = yearL + yearL / 4;
temp2 = temp2 % 7;
temp2 = temp2 + day + table_week[month - 1];
if (yearL % 4 == 0 && month < 3)
temp2--;
return (temp2 % 7);
}
/*********************************************************************
* @fn RTC_Calibration
*
* @brief The function `RTC_Calibration` calculates a calibration step value based on a given fast seconds per
* 30 days value.
*
* @param FastSecPer30days The `FastSecPer30days` parameter represents the number of fast seconds in a
* 30-day period. This value is used to calculate the calibration step for the RTC (Real-Time Clock)
* based on the deviation from the ideal timekeeping.
*
* @return none
*/
void RTC_Calibration(uint16_t FastSecPer30days)
{
float Deviation = 0.0;
u8 CalibStep = 0;
Deviation = FastSecPer30days * PPM_PER_SEC;
Deviation /= PPM_PER_STEP;
CalibStep = (u8)Deviation;
if (Deviation >= (CalibStep + 0.5))
CalibStep += 1;
if (CalibStep > 127)
CalibStep = 127;
BKP_SetRTCCalibrationValue(CalibStep);
printf("Calibration cab: %d\n", CalibStep);
}
/*********************************************************************
* @fn main
*
* @brief Main program.
*
* @return none
*/
int main(void)
{
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);
SystemCoreClockUpdate();
Delay_Init();
USART_Printf_Init(115200);
printf("SystemClk:%d\r\n", SystemCoreClock);
printf("ChipID:%08x\r\n", DBGMCU_GetCHIPID());
printf("RTC Calibration Test\r\n");
/* The code is initializing the TIM1 timer and the RTC (Real-Time Clock) module. */
TIM1_Base_Init(65535, SystemCoreClock / 1000000 - 1);
RTC_Init();
while (CalibrationFlag == 0)
;
printf("1CalibrationVal:%d\r\n", CalibrationVal);
if (CalibrationVal < 1000000)
{
printf("CalibrationVal:%d\r\n", CalibrationVal);
uint16_t FastSecPer30days = (1000000 - CalibrationVal)*3600*24*30/1000000;
printf("FastSecPer30days:%d\r\n", FastSecPer30days);
RTC_Calibration(FastSecPer30days);
}
while (1)
{
Delay_Ms(100);
}
}
注意EVT例程在MCU复位后时间会重置，重新从初始化配置时间开始运行，若不想MCU复位之后时间重置，可进行如下操作：在RTC初始化时，会有一个对后备数据寄存器的写入，后备数据寄存器可在VDD掉电后靠VBAT电源保存数据。可在RTC初始化时候加一个对后备数据寄存器读出数据的判断。若读出数据与写入数据一致，则时间不重置，继续RTC计数，若不一致，则重置重新开始计数。具体代码见上，如下图为RTC继续计数打印结果：
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