Posted on March 18, 2013 at 19:15Hello,
please look at following interrupt routines for capture/compare and uart receive
void TIM1_CC_IRQHandler(void)
{
uint32_t break_time, mab_time;
TIM_ClearITPendingBit(TIM1, TIM_IT_CC1);
break_time = TIM_GetCapture2(TIM1);
mab_time = TIM_GetCapture1(TIM1) - break_time;
/* use some tolerance for times */
if (break_time > 80 && break_time < 10e3 && mab_time >
😎 {
start_flag = 1;
TIM_ITConfig(TIM1, TIM_IT_CC1, DISABLE);
} else {
start_flag = 0;
}
}
void USART2_IRQHandler(void)
{
uint8_t rx_byte;
int16_t fe_flag;
USART_ClearITPendingBit(USART2, USART_IT_RXNE);
fe_flag = USART_GetFlagStatus(USART2, USART_FLAG_FE);
rx_byte = USART_ReceiveData(USART2); /* also clears FE flag */
if (fe_flag) {
TIM_ITConfig(TIM1, TIM_IT_CC1, ENABLE);
return;
}
if (start_flag)
byte_count = 0;
byte_count++;
}
CC and UART input are connected together and CC is measuring BREAK condition (low for 80us and more). When BREAK is detected UART receives a (constant) number of bytes. As I know that another BREAK will occur ''after some time'' I would like to disable CC interrupt. It can be enabled again when framing error arises. The theory is nice but this code works only when I'm not disabling the interrupt.
I have checked it with a scope (toggling a pin in interrupts) and I see what I'm expecting: the FE flag is set and interrupt fired during the BREAK. I see that there is enough time before edge which fires the CC interrupt. But even if I reenable the CC interrupt it is not fired anymore. I have also tried handle the interrupts through NVIC, but the situation is the same.
Do please someone see an error in my expectations?
regards
Jan
#interrupt
