TIM7 is stopping after working

[fab04]

Hi everybody,

I'm working on a STM32F446. I'm using the UART.

I've a function with switch/cases which instead of a function number fill a buffer.

ex :

switch(function) {

case 0x00 : Txbuffer[idx_trame++] = 0x00;break;

case 0x01 : Txbuffer[idx_trame++] = 0x00;break;

case 0x02 : Txbuffer[idx_trame++] = 0x00;break;

etc...

At the end of the function, I've the follwing function : HAL_UART_Transmit_DMA(...)

In parallel, I'm using the timer7 (triggered every 1ms).

It works well.

But, yesterday, I've added some cases, and when my software run into them, I see the tim7 stops (I've put a GPIO in the interrupt and a probe on it).

So, I see that before entering in the HAL_UART_Transmit_DMA function, it works and after it stops.

When I take a look on tim7 registers, everything seems to be OK, except UIF that keeps at 1 (so the interrupt is never resetted).

If you have some ideas, I'll be very happy.

[Bowman32]

The issue where TIM7's UIF flag remains set and the interrupt stops firing after calling HAL_UART_Transmit_DMA can be caused by inefficient clearing of the UIF flag before enabling interrupts, or by interrupt priority/masking conflicts introduced by DMA operations. Try to use a polling mechanism to clear UIF before enabling interrupts, verify all interrupt configurations, and ensure proper ISR implementation. Also, review interrupt priorities to avoid conflicts between DMA, UART, and TIM7.

[TDK]

TIM7 isn't stopping, the interrupt is just not being serviced.

If UIF=1 the interrupt will be called when the CPU gets time.

If the interrupt is never called, another interrupt is being processed. Since it happens after HAL_UART_Transmit_DMA, probably due to this. Possibly a UART error is happening and isn't being cleared.

Debug the code, hit pause, see where execution is at.