Tickless mode and software timers

Kernel
1

Hello,

I have a working project that is required to have a low power mode.

To the initial tests, I just activated the configUSE_TICKLESS_IDLE option, changed all the calls to osDelay() to HAL_Delay() to make sure the STM32 would never enter the PreSleepProcessing() function, to go to sleep mode.

What I noticed immediately was that the software timers don’t work at all. Please note, as I mentioned above, the MCU does not enter the PreSleepProcessing. This is intended as in this 1st step I want to have the same behavior without tickless idle active.

I’m running V10.3.1 on a STM32G473, and the code was generated by STM32CubeMX.

Anyone confirms that I cannot use software timers with tickless idle mode?

Thanks.

2

If I remember right, HAL_Delay is just a busy wait on the timer incrementing the required amount, verse osDelay() which will call vTaskDelay() which will block the task and let another task run.

If you have a task with priority above the TimerTask that doesn’t block, the timers can’t run.

3

If you do not want the core to enter sleep mode, why don’t you just remove the line that puts the core in the sleep mode?

4

@aggarg I divided the job in 2 parts:

  1. enable tickless idle mode, and make sure everything works as expected
  2. enter sleep mode, when some conditions are met

Right now I’m failing on #1

5

Enable tickless idle does not mean use need to use HAL_Delay. HAL_Delay is busy wait and as @richard-damon explained, it will most likely cause problems.