Posted on September 14, 2011 at 17:31 Hi, does anyone knows why the RxCounter in the interrupt routine always up-counting even the STM32 does not get into interrupt? I am trying some example codes about the USART. All the settings are the as usual, but when I run it in debug mode in IAR, I saw that the RxCounter started to count even I had not pressed run to start the program. Below are the codes in the interrupt routine. Anyone has any idea about that?
NbrOfDataToRead = 0x20;
void USART1_IRQHandler(void)
{
if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)
{
/* Read one byte from the receive data register */
RxBuffer[RxCounter++] = (USART_ReceiveData(USART1) & 0x7F);
if(RxCounter == NbrOfDataToRead)
{
/* Disable the USART Receive interrupt */
USART_ITConfig(USART1, USART_IT_RXNE, DISABLE);
}
}
if(USART_GetITStatus(USART1, USART_IT_TXE) != RESET)
{
/* Write one byte to the transmit data register */
USART_SendData(USART1, TxBuffer[TxCounter++]);
if(TxCounter == NbrOfDataToTransfer)
{
/* Disable the USART1 Transmit interrupt */
USART_ITConfig(USART1, USART_IT_TXE, DISABLE);
}
}
}
If I just put a variable++; alone in the routine, the crazy counting of that variable won't be happened. The crazy counting of the RxCounter is very strange, it won't stop even I stopped the program to execute that line.
#stm32-usart
