I can't make timer stop while debuging

[Carlos Zelayeta]

Posted on January 09, 2017 at 18:29

Hello.

I have a problem trying to stop a timer in debug mode.

I am using a NUCLEO-F072RB. I use timer 7, one of the basic timers, to generate an interrupt.

In order to be able to stop the timer in debug, mannually with breakpoint, I set the DBGMCU_APB1_FZ as stated in the reference manual (RM0091, 9.4).

My code is the following:

int main(void){ 
 /* Reset of all peripherals, Initializes the Flash interface and the Systick. */ 
 HAL_Init(); 
 /* Configure the system clock */ 
 SystemClock_Config(); 
 /* Initialize all configured peripherals */ 
 MX_TIM7_Init(); 
 /* USER CODE BEGIN 2 */
 HAL_DBGMCU_EnableDBGStandbyMode(); 
 HAL_DBGMCU_EnableDBGStopMode();
 DBGMCU->APB1FZ |= DBGMCU_APB1_FZ_DBG_TIM7_STOP; 
 while (1) 
 { 
 }
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When I run the debugger, none of the DBG registers changes its values and the timer doesn't stop when stopping execution.

I would like to know where the DBGMCU configuration lines should be placed, or if there is something else that needs to be configured.

Thanks in advance,

Carlos

#debug #timer #stm32f072

[Tesla DeLorean · Accepted solution]

Posted on January 09, 2017 at 19:25

Do you enable the DBGMCU clock on APB2 ??

RCC->APB2ENR |= RCC_APB2ENR_DBGMCUEN;

[Carlos Zelayeta]

Posted on January 09, 2017 at 19:54

Thank you very much!

I inserted the suggested line and it started working.

I paste the working code:

int main(void){ 
 /* Reset of all peripherals, Initializes the Flash interface and the Systick. */ 
 HAL_Init(); 
 /* Configure the system clock */ 
 SystemClock_Config(); 
 /* Initialize all configured peripherals */ 
 MX_TIM7_Init(); 
 /* USER CODE BEGIN 2 */
 RCC->APB2ENR |= RCC_APB2ENR_DBGMCUEN; //enable MCU debug module clock
 HAL_DBGMCU_EnableDBGStandbyMode(); 
 HAL_DBGMCU_EnableDBGStopMode();
 DBGMCU->APB1FZ |= DBGMCU_APB1_FZ_DBG_TIM7_STOP; //enable timer 7 stop 
 while (1) 
 { 
 }
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[Richard Delorme]

Posted on February 21, 2017 at 17:33

Thanks for the hint on the clock, I've been searching for an hour and this is the only place that mentions it and it fixed my issue.

[valentin]

Posted on June 19, 2017 at 01:51

Wow, thanks heaps Clive. I was struggling with that myself.

Suggestion to ST: Please implement that line in your __HAL_DBGMCU_FREEZE_xxx macros! I simply didn't know that was necessary and that's the whole point of having a macro, isn't it?

[jnewcomb]

Don't get caught out, like me obviously... This thread is specific to STM32F0xx series (RCC_APB2ENR @ bit 22 is RCC_APB2ENR_DBGMCUEN_Pos)

Other devices are different. Correct if mistaken, they don't even have a DBGMCUEN flag to enable.

[waclawek.jan]

Also in 'L0 and 'G0, but they call the given DBGEN there...

JW