// NVIC configuration

NVIC_InitTypeDef NVIC_InitStructure;

// Set the Vector Table base location at 0x08000000 !!!!!!
NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0);

// Configure one bit for preemption priority
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);
// Enable the EXTI0 Interrupt

//NVIC_InitStructure.NVIC_IRQChannel = EXTI9_5_IRQChannel; // !!!

NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);


// GPIO configuration
GPIO_InitTypeDef GPIO_InitStructure;
// Configure PA0 as input floating (EXTI Line0)
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE); // можно ли последовательно?
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
GPIO_Init(GPIOA, &GPIO_InitStructure);


// Configure EXTI Line0 to generate an interrupt on rising or falling edge
GPIO_EXTILineConfig(GPIOA,GPIO_PinSource0);

EXTI_InitStructure.EXTI_Line = EXTI_Line0;
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising_Falling;
EXTI_InitStructure.EXTI_LineCmd = ENABLE;
EXTI_Init(&EXTI_InitStructure);


NVIC_EnableIRQ(EXTI0_IRQn);

EXTI0_IRQHandler(void){

    GPIOC->ODR |= (GPIO_ODR_ODR9);
    //flags.button_pressed = 1;
    //turn_on_led();
    if(EXTI_GetITStatus(EXTI_Line0) != RESET)
    {
        //Handle the interrupt
        GPIOC->ODR |= (GPIO_ODR_ODR9);
        EXTI_ClearITPendingBit(EXTI_Line7);
    }
}

NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;

USART1_IRQHandler(void){

if (flags.wait_message_usart1){
switch (rx_stage){
case 1: // байт признака начала
if (USART1->DR == BEGIN){
rx_stage++;
} else {
rx_stage = 1; // в начало посылки
}
break;

case 2: // байт адреса
if (USART1->DR == ADDRESS_STM32){
rx_stage++;
} else {
rx_stage = 1;
}
break;

case 3: // байт функции
if (USART1->DR == FUNCTION){
rx_stage++;
} else {
rx_stage = 1;
}
break;

case 4: // старший байт crc
rx_stage++;
break;
case 5: // младший байт crc
rx_stage++;
break;
case 6: // старший байт признака конца CR
if (USART1->DR == CR){
rx_stage++;
} else {
rx_stage = 1;
}
break;

case 7: // младший байт признака конца LF
if (USART1->DR == LF){
rx_stage++;
} else {
rx_stage = 1;
}
break;
}
}
//GPIOC->ODR |= (GPIO_ODR_ODR9);

}

void EXTI0_IRQHandler(void) __attribute__((interrupt("IRQ")));
void EXTI0_IRQHandler(void)
{
  ... Ваш код ...
}