Timeout And Error Management; Example Of Fixed Timeout; Table 15: Timeout Values - ST STM32F2 User Manual

UM1940
HAL_USART_TxCpltCallback() and HAL_USART_ErrorCallback() should be linked in the
HAL_PPP_Process_DMA() function to the DMA transfer complete callback and the DMA
transfer Error callback by using the following statement:
HAL_PPP_Process_DMA (PPP_HandleTypeDef *hppp, Params....)
{
(...)
hppp->DMA_Handle->XferCpltCallback = HAL_UART_TxCpltCallback ;
hppp->DMA_Handle->XferErrorCallback = HAL_UART_ErrorCallback ;
(...)
}
2.12.4

Timeout and error management

2.12.4.1 Timeout management
The timeout is often used for the APIs that operate in Polling mode. It defines the delay
during which a blocking process should wait till an error is returned. An example is provided
below:
HAL_StatusTypeDef HAL_DMA_PollForTransfer(DMA_HandleTypeDef *hdma, uint32_t
CompleteLevel, uint32_t Timeout)
The timeout possible value are the following:
1 ... (HAL_MAX_DELAY -1)
Notes:
(1)
HAL_MAX_DELAY is defined in the stm32f2xx_hal_def.h as 0xFFFFFFFF
However, in some cases, a fixed timeout is used for system peripherals or internal HAL
driver processes. In these cases, the timeout has the same meaning and is used in the
same way, except when it is defined locally in the drivers and cannot be modified or
introduced as an argument in the user application.

Example of fixed timeout:

#define LOCAL_PROCESS_TIMEOUT 100
HAL_StatusTypeDef HAL_PPP_Process(PPP_HandleTypeDef)
{
(...)
timeout = HAL_GetTick() + LOCAL_PROCESS_TIMEOUT;
(...)
while(ProcessOngoing)
{
(...)
if(HAL_GetTick() >= timeout)
{
/* Process unlocked */
__HAL_UNLOCK(hppp);
hppp->State= HAL_PPP_STATE_TIMEOUT;
return HAL_PPP_STATE_TIMEOUT;
}
}
(...)
}
Timeout value
0
(1)
HAL_MAX_DELAY
DocID028236 Rev 2

Table 15: Timeout values

No poll : Immediate process check and exit
Infinite poll till process is successful
Overview of HAL drivers
Description
Timeout in ms
57/1371