[stm32f10x] standard library initialization issues

Hardware: STM32F103C8T6

Platform: ARM-MDK V5.11

The standard libraries provided by the STM32F series are initialized through structs. For example, here is a sample code for GPIO initialization:

  Gpio_inittypedef   gpio_initstructure;
  Gpio_initstructure.gpio_pin      = Gpio_pin_0 | gpio_pin_2;  Gpio_initstructure.gpio_speed   = Gpio_speed_50mhz;  Gpio_initstructure.gpio_mode    = gpio_mode_out_pp;   &gpio_initstructure);

First, define an initialization struct variable, then assign a value to the elements inside the struct based on the actual requirements, and finally call the initialization function to begin initialization.

I generally like to define this struct as a local variable, because the initialization process is usually called only once, and the problem comes.

This is a problem I encountered when using the TIM1 timer, I would like to use TIM1 to produce a 8us timing, but the result is 1ms timing. The code for the TIM1 timer initialization is as follows:

voidTimebaseconfig (void) {tim_timebaseinittypedef tim_timebasestructure; Tim_timebasestructure.tim_period=575; Tim_timebasestructure.tim_prescaler=0; Tim_timebasestructure.tim_clockdivision=0; Tim_timebasestructure.tim_countermode=tim_countermode_up; Tim_timebaseinit (Em4095_timebase,&tim_timebasestructure);    Tim_arrpreloadconfig (Em4095_timebase, ENABLE); /*TIM1 Enable counter*/tim_cmd (Em4095_timebase, ENABLE); /*Update Interrupt config*/tim_itconfig (Em4095_timebase, Tim_it_update, ENABLE);}

The problem is where the initialization structure is defined! At run time, look at the value of this struct:

　　

Because it is defined as a local variable, the value of the element inside the initialization struct is random, and my initialization function has less tim_repetitioncounter assignment, which should be set to 0 and the initial value is 0x80.

That is, repeat 128 times to produce a timed interrupt, about 1ms.

If the initialization struct is defined as a global variable:

　　

As you can see, when a struct is defined as a global variable, all values are initialized to 0.

　　Conclusion

Although the initialization structure is defined as a global variable, each element is initialized to 0, but not necessarily the value you need. Therefore, when initializing a peripheral, each element in the structure must be based on the

Actual demand assignment.

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[stm32f10x] standard library initialization issues