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218   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1.125MHz28   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=25Hz30    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]=034   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]=0036 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PB541   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_CCR247                                                                     //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 }