USARTEx Private Functions

Functions
static void	USARTEx_SetNbDataToProcess (USART_HandleTypeDef *husart)
	Calculate the number of data to process in RX/TX ISR. More...

Detailed Description

Function Documentation

USARTEx_SetNbDataToProcess()

static void USARTEx_SetNbDataToProcess ( USART_HandleTypeDef *  husart )

static

Calculate the number of data to process in RX/TX ISR.

Note

The RX FIFO depth and the TX FIFO depth is extracted from the USART configuration registers.

Parameters

husart

USART handle.

Return values

None

Definition at line 504 of file stm32l4xx_hal_usart_ex.c.

{
  uint8_t rx_fifo_depth;
  uint8_t tx_fifo_depth;
  uint8_t rx_fifo_threshold;
  uint8_t tx_fifo_threshold;
  /* 2 0U/1U added for MISRAC2012-Rule-18.1_b and MISRAC2012-Rule-18.1_d */
  uint8_t numerator[]   = {1U, 1U, 1U, 3U, 7U, 1U, 0U, 0U};
  uint8_t denominator[] = {8U, 4U, 2U, 4U, 8U, 1U, 1U, 1U};

  if (husart->FifoMode == USART_FIFOMODE_DISABLE)
  {
    husart->NbTxDataToProcess = 1U;
    husart->NbRxDataToProcess = 1U;
  }
  else
  {
    rx_fifo_depth = RX_FIFO_DEPTH;
    tx_fifo_depth = TX_FIFO_DEPTH;
    rx_fifo_threshold = (uint8_t)((READ_BIT(husart->Instance->CR3, USART_CR3_RXFTCFG) >> USART_CR3_RXFTCFG_Pos) & 0xFFU);
    tx_fifo_threshold = (uint8_t)((READ_BIT(husart->Instance->CR3, USART_CR3_TXFTCFG) >> USART_CR3_TXFTCFG_Pos) & 0xFFU);
    husart->NbTxDataToProcess = ((uint16_t)tx_fifo_depth * numerator[tx_fifo_threshold]) / (uint16_t)denominator[tx_fifo_threshold];
    husart->NbRxDataToProcess = ((uint16_t)rx_fifo_depth * numerator[rx_fifo_threshold]) / (uint16_t)denominator[rx_fifo_threshold];
  }
}