STM32F4 Cube HAL UART. Is it a bug or am I missing something?

Posted on November 06, 2015 at 04:33

I am using interrupt based UART IO (no DMA).

HAL_UART_Transmit_IT

function sets

EIE

bit in

CR3

register. According to STM32F407 datasheet (and real behaviour), this generates interrupt only in multi buffer mode (when

DMAR

bit is set).

EIE

enables interrupt generation for frame error (

FE

), overrun error (

ORE

), noise error (

NE

). This error, as I understand, only for receiving.

Part of

HAL_UART_IRQHandler

function:

tmp1 = __HAL_UART_GET_FLAG(huart, UART_FLAG_ORE);

tmp2 = __HAL_UART_GET_IT_SOURCE(huart, UART_IT_ERR);

/* UART Over-Run interrupt occurred ----------------------------------------*/

if

((tmp1 != RESET) && (tmp2 != RESET))

{

__HAL_UART_CLEAR_OREFLAG(huart);

huart->ErrorCode |= HAL_UART_ERROR_ORE;

}

if

(huart->ErrorCode != HAL_UART_ERROR_NONE)

{

/* Set the UART state ready to be able to start again the process */

huart->State = HAL_UART_STATE_READY;

HAL_UART_ErrorCallback(huart);

}

HAL_UART_IRQHandler

checks for each error. If error occurred and

EIE

bit is set, it resets UART state, but doesn't reset interrupt enabling bits, so

TXE

interrupt will be always generated, but

UART_Transmit_IT

function treats state

HAL_UART_STATE_READY

as invalid and doesn't do anything. Infinite loop.

Part of

UART_Transmit_IT

function:

static

HAL_StatusTypeDef UART_Transmit_IT(UART_HandleTypeDef *huart)

{

uint16_t* tmp;

uint32_t tmp1 = 0;

tmp1 = huart->State;

if

((tmp1 == HAL_UART_STATE_BUSY_TX) || (tmp1 == HAL_UART_STATE_BUSY_TX_RX))

{

}

else

{

return

HAL_BUSY;

}

}

Is it a bug in Cube HAL?

#stm32 #stm32f4 #hal #hal #uart #usart #interrupts #bug #stm32f4