5.20 NVIC 使用说明

#define VECT_TAB_FLASH_OFFSET ((uint32_t)0x00000000)
#define VECT_TAB_SRAM_OFFSET  ((uint32_t)0x00010000)

#define KEY_INPUT_PORT_CLK    RCC_AHB_PERIPHEN_GPIOA
#define KEY_INPUT_PORT        GPIOA
#define KEY_INPUT_PIN         GPIO_PIN_15
#define KEY_INPUT_EXTI_LINE   EXTI_LINE4
#define KEY_INPUT_LIN_SOURCE  EXTI_LINE_SOURCE4
#define KEY_INPUT_PORT_SOURCE GPIOA_PORT_SOURCE
#define KEY_INPUT_PIN_SOURCE  GPIO_PIN_SOURCE15
#define KEY_INPUT_IRQn        EXTI4_IRQn

    /*Configure key EXTI Line to key input Pin*/
    GPIO_ConfigEXTILine(KEY_INPUT_LIN_SOURCE, KEY_INPUT_PORT_SOURCE,KEY_INPUT_PIN_SOURCE);

    /*Configure key EXTI line*/
    EXTI_InitStruct(&EXTI_InitStructure);
    EXTI_InitStructure.EXTI_Line    = KEY_INPUT_EXTI_LINE;
    EXTI_InitStructure.EXTI_Mode    = EXTI_Mode_Interrupt;
    EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling; // EXTI_Trigger_Rising;
    EXTI_InitStructure.EXTI_LineCmd = ENABLE;
    EXTI_InitPeripheral(&EXTI_InitStructure);
    
    /* Configure two bits for preemption priority */
    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);

    /*Set key input interrupt priority*/
    NVIC_InitStructure.NVIC_IRQChannel                   = KEY_INPUT_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x01;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority        = 0x00;
    NVIC_InitStructure.NVIC_IRQChannelCmd                = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    if (EXTI_GetStatusFlag(KEY_INPUT_EXTI_LINE) != RESET)
    {
#ifdef VECT_TAB_SRAM
        log_info("EXTI4 IRQHandler is executed(SRAM) \r\n");
#else
        /* Key_Status */
        Key_Status = ENABLE;
        log_info("EXTI4 IRQHandler is executed(FLASH) \r\n");
#endif
        /* Clears the SEL Button EXTI line pending bits */
        EXTI_ClrStatusFlag(KEY_INPUT_EXTI_LINE);
    }

        if (Key_Status == ENABLE)
        {
            log_info("Sets the vector table location and Offset \r\n");

            /* Vector Table Relocation in Internal SRAM. */
            NVIC_SetVectorTable(NVIC_VectTab_RAM, VECT_TAB_SRAM_OFFSET);

            while (1)
                ;
        }

    TIM_InitTimBaseStruct(&TIM_TimeBaseStructure);
    TIM_TimeBaseStructure.Period    = 50000-1;
    TIM_TimeBaseStructure.Prescaler = ((RCC_Clocks.HclkFreq / 50000) - 1);
    TIM_TimeBaseStructure.ClkDiv    = TIM_CLK_DIV1;
    TIM_TimeBaseStructure.CounterMode   = TIM_CNT_MODE_UP;
    TIM_InitTimeBase(GTIM3, &TIM_TimeBaseStructure);

    /* Immediate load of GTIM3 Precaler values */
    TIM_ConfigPrescaler(GTIM3, ((RCC_Clocks.HclkFreq / 50000) - 1),TIM_PSC_RELOAD_MODE_IMMEDIATE);

    /* Clear GTIM3 update pending flags */
    TIM_ClearFlag(GTIM3, TIM_FLAG_UPDATE);

    /* Enable the GTIM3 Interrupt */
    NVIC_InitStructure.NVIC_IRQChannel                   = GTIM3_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority        = 0;
    NVIC_InitStructure.NVIC_IRQChannelCmd                = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    /* Enable GTIM3 Update interrupts */
    TIM_ConfigInt(GTIM3, TIM_INT_UPDATE,ENABLE);

    /* GTIM3 enable counters */
    TIM_Enable(GTIM3,ENABLE);

        while (Key_Status == DISABLE)
        {
        }
        log_info("Disable irq \r\n");
        /* This instruction raises the execution priority to 0. This prevents all
           exceptions with configurable priority from activating, other than through
           the HardFault fault escalation mechanism. */
        __disable_irq();

        while(GPIO_ReadInputDataBit(KEY_INPUT_PORT,KEY_INPUT_PIN) == RESET)
        {
        
        }
        while(GPIO_ReadInputDataBit(KEY_INPUT_PORT,KEY_INPUT_PIN) == SET)
        {
        
        }

        log_info("enable irq \r\n");

    if (EXTI_GetStatusFlag(KEY_INPUT_EXTI_LINE) != RESET)
    {
        if (Key_Status == ENABLE)
        {
            Key_Status = DISABLE;
        }
        else
        {
            Key_Status = ENABLE;
        }
        /* Clears the SEL Button EXTI line pending bits. */
        EXTI_ClrStatusFlag(KEY_INPUT_EXTI_LINE);
    }

    /* Clear GTIM3 update interrupt */
    TIM_ClearFlag(GTIM3, TIM_INT_UPDATE);

    /* GTIM3 IRQHandler */
    log_info("GTIM3 IRQHandler \r\n");

    KeyInputExtiInit(KEY_INPUT_PORT, KEY_INPUT_PIN);
    /* Configure the SysTick Handler Priority: Preemption priority(0) and subpriority */
    NVIC_SetPriority(SysTick_IRQn, NVIC_EncodePriority(NVIC_GetPriorityGrouping(), PreemptionPriorityValue, 0));

    log_info("EXTI4 IRQHandler Start \r\n");
    if (EXTI_GetStatusFlag(KEY_INPUT_EXTI_LINE) != RESET)
    {
        /* Generate SysTick exception */
        SCB->ICSR |= 0x04000000;

        /* Clears the SEL Button EXTI line pending bits */
        EXTI_ClrStatusFlag(KEY_INPUT_EXTI_LINE);
    }
    log_info("EXTI4 IRQHandler End \r\n");

void SysTick_Handler(void)
{
    log_info("SysTick IRQHandler \r\n");
    /* If the EXTI0 IRQ Handler was preempted by SysTick Handler */
    if (NVIC_GetActive(KEY_INPUT_IRQn) != 0)
    {
        Key_Status = 1;
    }
    else
    {
        Key_Status = 2;
    }
}

    while (1)
    {
        if (Key_Status == 1)
        {
            log_info("Key_Status = 1 \r\n");
            /* Configure the SysTick Handler Priority: Preemption priority(2) and subpriority */
            NVIC_SetPriority(SysTick_IRQn,
                             NVIC_EncodePriority(NVIC_GetPriorityGrouping(), PreemptionPriorityValue + 2, 0));
        }
        else if (Key_Status == 2)
        {
            log_info("NVIC IRQ Priority Test End \r\n");
        }
        else
        {
            log_info("Key_Status = 0 \r\n");
        }

        /* Insert delay Time */
        Delay(0x8FFFFF);
    }