[STM32 learning] (8) stm32f1 general timer configuration

（1） Enable timer clock

 

         RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4,ENABLE);// Can make TIM4 The clock

（2） Initialize timer parameters , Contains auto reload values , Division coefficient , Counting method, etc

voidTIM_TimeBaseInit(TIM_TypeDef*TIMx,TIM_TimeBaseInitTypeDef* TIM_TimeBaseInitStruct);

typedef struct

{

uint16_t TIM_Prescaler; // Timer prescaler

uint16_t TIM_CounterMode; // Count mode

uint32_t TIM_Period; // Timer cycle

uint16_t TIM_ClockDivision; // The clock frequency division

uint8_t TIM_RepetitionCounter; // Repeat counter

} TIM_TimeBaseInitTypeDef;

After understanding the functions of structure members , You can configure , for example ：

TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;

TIM_TimeBaseInitStructure.TIM_Period=1000; // Auto load values

TIM_TimeBaseInitStructure.TIM_Prescaler=35999; // Division coefficient

TIM_TimeBaseInitStructure.TIM_ClockDivision=TIM_CKD_DIV1;

TIM_TimeBaseInitStructure.TIM_CounterMode=TIM_CounterMode_Up; // Set up count mode

TIM_TimeBaseInit(TIM4,&TIM_TimeBaseInitStructure);

          The calculation formula of timer timing time is as follows ：Tout= ((per+1)*(psc+1))/Tclk;

（3） Set timer interrupt type , And enable

void TIM_ITConfig(TIM_TypeDef* TIMx, uint16_t TIM_IT, FunctionalState NewState);

（4） Set timer interrupt priority , Enable timer interrupt channel

NVIC The initialization library function is NVIC_Init();

typedef struct

{

uint8_t NVIC_IRQChannel; // Interrupt source

uint8_t NVIC_IRQChannelPreemptionPriority; // preemption

uint8_t NVIC_IRQChannelSubPriority; // Response priority

FunctionalState NVIC_IRQChannelCmd; // Interrupt enable or disable

} NVIC_InitTypeDef;

After understanding the functions of structure members , You can configure , for example ：

NVIC_InitTypeDef NVIC_InitStruct;

NVIC_InitStruct.NVIC_IRQChannel=TIM4_IRQn;

NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority=2;

NVIC_InitStruct.NVIC_IRQChannelSubPriority=3;

NVIC_InitStruct.NVIC_IRQChannelCmd=ENABLE;

NVIC_Init(&NVIC_InitStruct);

（5） Turn on timer

void TIM_Cmd(TIM_TypeDef* TIMx, FunctionalState NewState);

（6） Write timer interrupt service function

TIM4_IRQHandler

ITStatus TIM_GetITStatus(TIM_TypeDef* TIMx, uint16_t TIM_IT);

if(TIM_GetITStatus(TIM4,TIM_IT_Update))

{

...// perform TIM4 Update interrupt internal control

}

void TIM_ClearITPendingBit(TIM_TypeDef* TIMx, uint16_t TIM_IT);

There are also two functions in the firmware library to read the status flag bit and clear the interrupt flag bit , The functions are TIM_GetFlagStatus and TIM_ClearFlag

The code is as follows ：

main.c

#include "stm32f10x.h"                  // Device header
#include "stm32f10x_gpio.h"
#include "sys.h"
#include "led.h"


void delay(void);
unsigned char cnt=0;

// Universal timer 3 Interrupt initialization 
// Here, the clock is selected as APB1 Of 2 times , and APB1 by 36M
//arr： Auto reload value .
//psc： Clock presplitting frequency 
// Here's a timer 3!
void TIM3_Int_Init(u16 arr,u16 psc)
{
    TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
    NVIC_InitTypeDef NVIC_InitStructure;

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); // Clock enable 

    // Timer TIM3 initialization 
    TIM_TimeBaseStructure.TIM_Period = arr; // Set the value of the auto reload register cycle for the next update event load activity    
    TIM_TimeBaseStructure.TIM_Prescaler =psc; // Set as TIMx Prescaled value of clock frequency divisor 
    TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1; // Set the clock split :TDTS = Tck_tim
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  //TIM Upcount mode 
    TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); // Initialize... According to the specified parameters TIMx Unit of time base 

    TIM_ITConfig(TIM3,TIM_IT_Update,ENABLE ); // Enable to designate TIM3 interrupt , Allow update interrupt 

    // Interrupt priority NVIC Set up 
    NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;  //TIM3 interrupt 
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;  // Take precedence 0 level 
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;  // From the priority 3 level 
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ The channel is energized 
    NVIC_Init(&NVIC_InitStructure);  // initialization NVIC register 


    TIM_Cmd(TIM3, ENABLE);  // Can make TIMx                     
}
// Timer 3 Interrupt service routine 
void TIM3_IRQHandler(void)   //TIM3 interrupt 
{
    if (TIM_GetITStatus(TIM3, TIM_IT_Update) != RESET)  // Check TIM3 Whether the update interrupt occurs or not 
    {
		cnt++;
		TIM_ClearITPendingBit(TIM3, TIM_IT_Update  );  // eliminate TIMx Update interrupt flag 
		if(cnt>=15)
		{
			LED1=!LED1;
			cnt=0;
		}
    }
}
//LED1 The flashing period is 500ms,LED0 The flashing period is 200ms, The phenomenon seen is LED1 Slow flicker ,LED0 Flash fast 
int main(void)
{       
	LED_init_wt();	
    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2); // Set up NVIC Interrupt grouping 2:2 Bit preemption priority ,2 Bit response priority 
    TIM3_Int_Init(4999,7199);//10Khz The counting frequency of , Count to 5000 by 500ms  
    while(1)
    {
        LED0=!LED0;
        delay();         
    }
} 

void delay(void)
{
	int i,j;
	for(i=0;i<400;i++)
	{
		for(j=0;j<400;j++);
	}
}

led.h

#ifndef __LED_H
#define __LED_H	 
#include "sys.h"
								  
// 
#define LED0 PCout(0)// PC0
#define LED1 PCout(1)// PC1
#define LED2 PCout(2)// PC2

void LED_init_wt(void);// initialization 

		 				    
#endif

led.c

#include "led.h"

void LED_init_wt(void)
{
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC,ENABLE);	//	 To enable or disable APB2 Peripheral clock 
	GPIO_InitTypeDef GPIO_InitStruct;	//	 Defining structure   Contains peripherals GPIO Configuration information 	
	GPIO_InitStruct.GPIO_Pin = GPIO_Pin_0|GPIO_Pin_1;	//   Select all pins 
	GPIO_InitStruct.GPIO_Mode = GPIO_Mode_Out_PP;	//	 Push pull output 
	GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;	//	 Maximum output rate 50MHz
	GPIO_Init(GPIOC,&GPIO_InitStruct);	//	 according to GPIO_InitStruct The parameter specified in GPIOA register 
}

The code is done . Please test the effect by yourself .O(∩_∩)O