[stm32] 中断

 1 #include  "stm32f10x.h"
 2 #include  "stm32f10x_tim.h"
 3 #include  "misc.h"
 4 #include  "stm32f10x_gpio.h"
 5 
 6 unsigned int CCR2_Val=45000; 
 7 extern void time_ini(void);
 8 unsigned int capture1=0;
 9 TIM_TimeBaseInitTypeDef  TIM3_TimeBaseStructure;
10 TIM_OCInitTypeDef  TIM3_OCInitStructure;
11 TIM_BDTRInitTypeDef TIM3_BDTRInitStructure;
12 
13 void time_ini(void){
14   GPIO_InitTypeDef GPIO_InitStructure;
15   RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);            //定时器3 时钟使能
16   
17   GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;                        //PB5复用为TIM3的通道2
18   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
19   GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
20   GPIO_Init(GPIOB, &GPIO_InitStructure);
21 
22   /* TIM3局部复用功能开启     在TIM3的局部复用开启时，PB5会被复用为TIM3_CH2*/
23   GPIO_PinRemapConfig(GPIO_PartialRemap_TIM3 , ENABLE);    
24 
25   /* Time Base configuration */
26   /*-------------------------------------------------------------------
27   TIM3CLK=72MHz  预分频系数Prescaler=63 经过分频 定时器时钟为1.125MHz
28   捕获/比较寄存器2 TIM3_CCR2= CCR2_Val 
29   2通道产生的更新频率是=1.125MHz/CCR2_Val=25Hz
30    
31   -------------------------------------------------------------------*/
32   TIM3_TimeBaseStructure.TIM_Prescaler = 630;                        //预分频器TIM3_PSC=630     
33   TIM3_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;        //计数器向上计数模式 TIM3_CR1[4]=0
34   TIM3_TimeBaseStructure.TIM_Period =0xffff;                        //自动重装载寄存器TIM3_APR                   
35   TIM3_TimeBaseStructure.TIM_ClockDivision = 0x0;                    //时钟分频因子 TIM3_CR1[9:8]=00
36 
37   TIM_TimeBaseInit(TIM3,&TIM3_TimeBaseStructure);                    //写TIM3各寄存器参数
38   
39   TIM3_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle ;                //TIM3_CCMR1[14:12]=011  翻转 当TIM3_CCR2=TIM3_CNT时，翻转OC2REF的电平 
40   TIM3_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;    //输入/捕获2输出允许  OC2信号输出到对应的输出引脚PB5
41   TIM3_OCInitStructure.TIM_Pulse =CCR2_Val;                            //若CC1通道配置为输出：CCR2是装入当前捕获/比较2 TIM3_CCR2寄存器的值（预装载值）。
42                                                                       //当前捕获/比较寄存器包含了与计数器TIM3_CNT比较的值，并且在OC端口上输出信号
43   TIM3_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;            //输出极性  低电平有效 TIM3_CCER[5]=1;
44 
45   TIM_OC2Init(TIM3, &TIM3_OCInitStructure);
46   TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Disable);                //TIM3_CCMR1[1]=0  禁止TIM3_CCR2寄存器的预装载功能，可随时写入TIM3_CCR2
47                                                                     //且新值马上起作用
48  
49    TIM_Cmd(TIM3,ENABLE);                                            //启动定时器3 TIM3_CR1[0]=1;  
50    TIM_ITConfig(TIM3,TIM_IT_CC2,ENABLE);                             //TIM3_DIER[2]=1  允许捕获/比较2中断
51 }
52 
53 void RCC_Configuration(void){
54 
55   SystemInit(); 
56   RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE); 
57   RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_GPIOC 
58                           | RCC_APB2Periph_GPIOD| RCC_APB2Periph_GPIOE , ENABLE);
59 }
60 
61 void NVIC_Configuration(void)
62 {
63   NVIC_InitTypeDef NVIC_InitStructure;
64   NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);
65 
66   NVIC_InitStructure.NVIC_IRQChannel =TIM3_IRQn ;               //配置定时器中断 
67   NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
68   NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
69   NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
70   NVIC_Init(&NVIC_InitStructure);      
71 }
72 
73 int main(void)
74 {    
75   RCC_Configuration();                        //系统时钟设置及外设时钟使能                         
76   NVIC_Configuration();                         //中断源配置
77   time_ini();                                 //定时器3的初始化
78   while(1);
79 }
80 
81 void TIM3_IRQHandler(void){ 
82         
83  if (TIM_GetITStatus(TIM3, TIM_IT_CC2) != RESET)        //判断状态寄存器 TIM3_SR[2] 是否发生了捕获/比较2 中断
84   {
85     TIM_ClearITPendingBit(TIM3, TIM_IT_CC2);            //软件清除状态寄存器 TIM3_SR[2] 捕获/比较2 中断中断标志
86 
87     capture1 = TIM_GetCapture2(TIM3);                    //获取TIM3_CCR2的预装值
88     TIM_SetCompare2(TIM3, capture1+ CCR2_Val);            //和CCR2_Val累加后装入TIM3_CCR2     这是为了配合计数器值的递增。以在下一次作出比较。
89     
90   }
91  
92 }