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NITIN RAWAL
NITIN RAWAL
Associate
April 11, 2018
Solved

what is the difference between Transmission complete Interrupt(USART_CR1_TCIE) and TXE interrupt enable(USART_CR1_TXEIE) .

  • April 11, 2018
  • 2 replies
  • 1676 views
Posted on April 11, 2018 at 11:01

My  code is run on STM32F427ZIxx

SET_BIT(huart2.Instance->CR1, USART_CR1_TXEIE);

void USART2_IRQHandler(void)

{

/* USER CODE BEGIN USART2_IRQn 0 */

/* USER CODE END USART2_IRQn 0 */

HAL_UART_IRQHandler(&huart2);

/* USER CODE BEGIN USART2_IRQn 1 */

HAL_UART_Transmit(&huart3,(uint8_t *)'\r\nTransmission Complete Interrupt',33,100);

}

when i am reading UART3 it is going infinite but CLEAR_BIT(huart2.Instance->CR1, USART_CR1_TXEIE); in ISR, giving two times print of.

vs  what is USART_CR1_TCIE  ????    

    This topic has been closed for replies.
    Best answer by AvaTar
    Posted on April 11, 2018 at 12:31

    TXE indicates the TX register is empty, and available again. The last value had just been moved to the send hardware.

    The actual transmission might not yet have been started.

    TC means the hardware has finished the transmission, the character has 'left' the device. This might take comparatively long.

    void USART2_IRQHandler(void)

    {

    HAL_UART_Transmit(&huart3,(uint8_t *)'\r\nTransmission Complete Interrupt',33,100);

    }

    Not sure what the Cube generated code is based upon, but calling synchronous output functions (like printf()) from within an interrupt handler is a recipe for disaster.

    2 replies

    AvaTar
    AvaTarBest answer
    Senior III
    April 11, 2018
    Posted on April 11, 2018 at 12:31

    TXE indicates the TX register is empty, and available again. The last value had just been moved to the send hardware.

    The actual transmission might not yet have been started.

    TC means the hardware has finished the transmission, the character has 'left' the device. This might take comparatively long.

    void USART2_IRQHandler(void)

    {

    HAL_UART_Transmit(&huart3,(uint8_t *)'\r\nTransmission Complete Interrupt',33,100);

    }

    Not sure what the Cube generated code is based upon, but calling synchronous output functions (like printf()) from within an interrupt handler is a recipe for disaster.

    NITIN RAWAL
    NITIN RAWALAuthor
    Associate
    April 12, 2018
    Posted on April 12, 2018 at 06:35

    thanks for valuable answer..

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