Конфигурирование USART

int main(void)

{

  /*!< At this stage the microcontroller clock setting is already configured,

       this is done through SystemInit() function which is called from startup

       file (startup_stm32f0xx.s) before to branch to application main.

       To reconfigure the default setting of SystemInit() function, refer to

       system_stm32f0xx.c file

     */

  Configure_GPIO_LED();

  Configure_GPIO_USART1();

  Configure_USART1();

  Configure_GPIO_Button();

  Configure_EXTI();

  /* Start transmission in button IRQ handler */

  /* Infinite loop */

  while (1)

  {

  }

}

/**

  * @brief  This function :

             - Enables GPIO clock

             - Configures the Green LED pin on GPIO PC9

             - Configures the Orange LED pin on GPIO PC8

  * @param  None

  * @retval None

  */

__INLINE void Configure_GPIO_LED(void)

{

  /* Enable the peripheral clock of GPIOC */

  RCC->AHBENR |= RCC_AHBENR_GPIOCEN;

  /* Select output mode (01) on PC8 and PC9 */

  GPIOC->MODER = (GPIOC->MODER & ~(GPIO_MODER_MODER8 | GPIO_MODER_MODER9)) \

                 | (GPIO_MODER_MODER8_0 | GPIO_MODER_MODER9_0);

}

/**

  * @brief  This function :

             - Enables GPIO clock

             - Configures the USART1 pins on GPIO PB6 PB7

  * @param  None

  * @retval None

  */

__INLINE void Configure_GPIO_USART1(void)

{

  /* Enable the peripheral clock of GPIOA */

  RCC->AHBENR |= RCC_AHBENR_GPIOAEN;

  /* GPIO configuration for USART1 signals */

  /* (1) Select AF mode (10) on PA9 and PA10 */

  /* (2) AF1 for USART1 signals */

  GPIOA->MODER = (GPIOA->MODER & ~(GPIO_MODER_MODER9|GPIO_MODER_MODER10))\

                 | (GPIO_MODER_MODER9_1 | GPIO_MODER_MODER10_1); /* (1) */

  GPIOA->AFR[1] = (GPIOA->AFR[1] &~ (GPIO_AFRH_AFRH1 | GPIO_AFRH_AFRH2))\

                  | (1 << (1 * 4)) | (1 << (2 * 4)); /* (2) */

}

/**

  * @brief  This function configures USART1.

  * @param  None

  * @retval None

  */

__INLINE void Configure_USART1(void)

{

  /* Enable the peripheral clock USART1 */

  RCC->APB2ENR |= RCC_APB2ENR_USART1EN;

  /* Configure USART1 */

  /* (1) oversampling by 16, 9600 baud */

  /* (2) 8 data bit, 1 start bit, 1 stop bit, no parity */

  USART1->BRR = 480000 / 96; /* (1) */

  USART1->CR1 = USART_CR1_TE | USART_CR1_UE; /* (2) */

  /* polling idle frame Transmission */

  while((USART1->ISR & USART_ISR_TC) != USART_ISR_TC)

  {

    /* add time out here for a robust application */

  }

  USART1->ICR |= USART_ICR_TCCF;/* clear TC flag */

  USART1->CR1 |= USART_CR1_TCIE;/* enable TC interrupt */

  /* Configure IT */

  /* (3) Set priority for USART1_IRQn */

  /* (4) Enable USART1_IRQn */

  NVIC_SetPriority(USART1_IRQn, 0); /* (3) */

  NVIC_EnableIRQ(USART1_IRQn); /* (4) */

}