Timer initialisation to *not* set the ARPE bit ?

[pr]

I would like to know what is the correct way to disable a timer’s ARR preload function using the HAL library ? And once that’s done, does the ARPE bit stay low for the whole runtime, or does it have to be cleared again regularly or after specific events? (If yes, which?)

[TDK · Accepted solution]

Set htimx.Init.AutoReloadPreload to TIM_AUTORELOAD_PRELOAD_DISABLE before you call HAL_TIM_***_Init().

It'll stay the way you initialize it unless you re-initialize it with TIM_AUTORELOAD_PRELOAD_ENABLE.

[pr]

The timer handle's Init member is of type TIM_Base_InitTypeDef:

typedef struct
{
  TIM_TypeDef 
  TIM_Base_InitTypeDef        Init;
  HAL_TIM_ActiveChannel       Channel;
  DMA_HandleTypeDef           *hdma[7];
  HAL_LockTypeDef             Lock;
  __IO HAL_TIM_StateTypeDef   State;
}TIM_HandleTypeDef;
 
typedef struct
{
  uint32_t Prescaler;  
  uint32_t CounterMode;
  uint32_t Period; 
  uint32_t ClockDivision; 
  uint32_t RepetitionCounter; 
} TIM_Base_InitTypeDef;

There is no htimx.Init.AutoReloadPreload -- am I using an outdated version of the HAL library ? (It came bundled as part of the GNU MCU Eclipse STM32F4 project template.)

[TDK]

Yes, seems like an old version. Id consider downloading STMCubeMX and using that to generate the initialization code.
You could also manipulate ARPE manually if comfortable.

[pr]

I updated my drivers and that worked