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Stm32L151RCxxx USART Hang issue, Interrupt Based TX/RX simultaneously

Question asked by singh.ishmeet on Jan 13, 2014
Latest reply on Jan 14, 2014 by Clive One
Hi,


I am running USART3, on 921600 BaudRate, using RTS CTS, I am always facing system hang when I try to do RX and TX simultaneously. I have pasted the main and IRQ code. IRQ is designed to Transmit a char 'A' while dropping all received data. Hang happens when we disable 
USART_ITConfig(USART3, USART_IT_TXE, DISABLE);


Uart_Configuration()...
  
    USART_ClockInitStructure.USART_Clock = USART_Clock_Disable;
    USART_ClockInitStructure.USART_CPOL = USART_CPOL_Low;
    USART_ClockInitStructure.USART_CPHA = USART_CPHA_2Edge;
    USART_ClockInitStructure.USART_LastBit = USART_LastBit_Disable;
    USART_ClockInit(USART3, &USART_ClockInitStructure);
  
    USART_InitStructure.USART_Mode = (USART_Mode_Tx|USART_Mode_Rx);
    USART_InitStructure.USART_BaudRate = u32BaudRate;
    USART_OverSampling8Cmd(USART3, DISABLE);
    USART_InitStructure.USART_Parity = USART_Parity_No ;
    USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_RTS_CTS;
    USART_InitStructure.USART_WordLength = USART_WordLength_8b;
    USART_InitStructure.USART_StopBits = USART_StopBits_1;
  
    USART_Init(USART3, &USART_InitStructure); 
    USART_ITConfig(USART3,USART_IT_TXE, DISABLE);
    USART_ITConfig(USART3, USART_IT_RXNE, ENABLE);
    USART_Cmd(USART3, ENABLE);

Main.c
uint8_t UART_TransmitData(void)
{
if(u8IntTxFlag==1)
{
u8IntTxFlag=0;
USART_ITConfig(USART3, USART_IT_TXE, ENABLE);     
return TRUE;
}
return FALSE;
}
   
   
void USART3_IRQHandler(void)
{
/* Implemented full duplex serial communication */
/*  UART RX  */
if(USART_GetITStatus(USART3, USART_IT_RXNE) != RESET)
{
USART_ReceiveData(USART3);
}
   
/*    UART TX    */
if(USART_GetITStatus(USART3, USART_IT_TXE) != RESET)
{
if(USART_GetFlagStatus(USART3, USART_FLAG_CTS) == RESET)
{
    while(USART_GetFlagStatus(USART3, USART_FLAG_TXE) == RESET);
    USART_SendData(USART3, 'A');
    while(USART_GetFlagStatus(USART3, USART_FLAG_TC) == RESET);
    USART_ClearFlag(USART3, USART_FLAG_TC);
    USART_ITConfig(USART3, USART_IT_TXE, DISABLE);
    u8IntTxFlag=1;
}
else
{
    USART_ClearFlag(USART3, USART_FLAG_CTS);
}
}
   
}
   
   
int main(void)
{
  RCC_ClocksTypeDef RCC_Clocks;
   
  RCC_Configuration();
  RCC_GetClocksFreq(&RCC_Clocks);
  SysTick_Config(RCC_Clocks.HCLK_Frequency / 2000);
   
  NVIC_Configuration();
   
  Init_GPIOs();
   
  SerialUARTConfig(921600, 0, 1, 8, 1);
   
   while(1)
   {
         UART_TransmitData();
         f_SleepMs(5);
   
   }
   return 0;
}


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