[MM32硬件] mm32f0010 mm32f0020 测LSI时钟频率

void Iwdg_Irq_ON(void)

{

    NVIC_InitTypeDef NVIC_InitStructure;

    EXTI_InitTypeDef EXTI_InitStructure;



    EXTI_DeInit();

    EXTI_StructInit(&EXTI_InitStructure);

    EXTI_InitStructure.EXTI_Line = EXTI_Line17 ;

    EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt ;

    EXTI_InitStructure.EXTI_Trigger =   EXTI_Trigger_Rising_Falling  ;

    EXTI_InitStructure.EXTI_LineCmd = ENABLE;

    EXTI_Init(&EXTI_InitStructure);

    EXTI_ClearITPendingBit(EXTI_Line17);



    NVIC_InitStructure.NVIC_IRQChannel = WWDG_IWDG_IRQn;

    NVIC_InitStructure.NVIC_IRQChannelPriority = 0;

    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

    NVIC_Init(&NVIC_InitStructure);

}





#define IWDG_FLAG_IVU               ((uint16_t)0x0004)

void IVU_CheckStatus(void)

{

    while(1) {

        if(IWDG_GetFlagStatus(IWDG_FLAG_IVU) == RESET) {

            break;

        }

    }

}

void Write_Iwdg_ON(u16 IWDG_Prescaler, u16 Reload)

{

    RCC_LSICmd(ENABLE);

    while(RCC_GetFlagStatus(RCC_FLAG_LSIRDY) == RESET);



    PVU_CheckStatus();

    IWDG_WriteAccessCmd(0x5555);

    IWDG_SetPrescaler(IWDG_Prescaler);



    RVU_CheckStatus();

    IWDG_WriteAccessCmd(0x5555);

    IWDG_SetReload(Reload & 0xfff);



    IVU_CheckStatus();

    IWDG_WriteAccessCmd(0x5555);

    IWDG->IGEN = 0x50;



    IWDG_ReloadCounter();

    IWDG_WriteAccessCmd(0x5555);

    IWDG->CR |= 1;

    IWDG_Enable();

}



void PWR_STOP_iwdg_Init(void)

{

    u16 i;

    RCC_APB1PeriphClockCmd(RCC_APB1ENR_PWREN, ENABLE);

//    deleyNop(10000);

//    for(i = 0; i < 10; i++) {

//        LED1_TOGGLE();

//        deleyNop(1000);

//    }

    Iwdg_Irq_ON();

    Write_Iwdg_ON(IWDG_Prescaler_4, 2500+0x50);//计算方法 time = Reload/40000*IWDG_Prescaler   s





}





void my_delay_ms(u16 m)    ;

u16 low=0;





int main(void)

{GPIO_InitTypeDef  GPIO_InitStructure;

    u16 time_y;

        float HZ;

    //mco输出LSI时钟 PA7迎角

      RCC_LSICmd(ENABLE);

    while(RCC_GetFlagStatus(RCC_FLAG_LSIRDY) == RESET);

    RCC_AHBPeriphClockCmd(RCC_AHBENR_GPIOA, ENABLE);

    RCC_APB1PeriphClockCmd(RCC_APB1ENR_SYSCFG, ENABLE);



    GPIO_StructInit(&GPIO_InitStructure);

    GPIO_InitStructure.GPIO_Pin  = GPIO_Pin_7;

    GPIO_InitStructure.GPIO_Speed =  GPIO_Speed_50MHz;

    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;



    GPIO_Init(GPIOA, &GPIO_InitStructure);

    GPIO_PinAFConfig( GPIOA, GPIO_PinSource7, GPIO_AF_3);

    RCC_MCOConfig(RCC_MCO_LSI);

    

    USART1_Init();



    time_x = 2; //用处不大可以删除

    time_y = time_x; //用处不大可以删除

    PWR_STOP_iwdg_Init();



    TIM3_Int_Init(0xffff-1,time_y-1);//2分频

    printf("ok");

    

    while(1)

    {

        if(LSI_HZ!=low )//频率不同时重新计算 实际用处不大可以删除

        {

            HZ=48000000/time_y;//得到分频频率

            HZ=(LSI_HZ+0xffff*time_num)/HZ; //实际时间

            time_num = 0;//定时器溢出计数

            printf("%f",HZ);  //输出实际时间      

            HZ =4/HZ*2500;  //得到实际时间按看门狗公式反推频率

            printf("   %.2f\r\n",HZ);//输出实际频率

        low =LSI_HZ ;

        }

//    printf("%d ",aaa);

//        my_delay_ms(1000);

    }

}