定时器同步问题

william_zeng

u8 TIM2_CCR4_Val = 4 ;

u16 TIM3_CCR3_Val = 30000 ;

u8 TIM4_CCR3_Val = 30 ;

void TIMER_Configuration()

{

    #define PrescalerValue  10 - 1 

#define PrescalerValue1  2000 - 1 

#define PrescalerValue2  2 - 1 

        TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;

    TIM_OCInitTypeDef TIM_OCInitStructure;     

          

    // time2  channel 4 100k/2/4/2=6250Hz  Toggle  slave */

// time3  channel 3 60M/2000/30000/2=0.5Hz timing */

    // time4  channel 3 60M/10/30/2= 100KHz  Toggle master     */

    TIM_DeInit(TIM2);

TIM_DeInit(TIM3);

    TIM_DeInit(TIM4);

    TIM_InternalClockConfig(TIM3);

TIM_InternalClockConfig(TIM4);

      //* time3 channel 3  B13 */

      TIM_TimeBaseStructure.TIM_Prescaler = 0;

      TIM_TimeBaseStructure.TIM_ClockDivision = 0;

      TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; 

    TIM_TimeBaseStructure.TIM_Period = 65536 - 1;

              TIM_TimeBaseInit(TIM3,&TIM_TimeBaseStructure);

TIM_PrescalerConfig(TIM3, PrescalerValue1, TIM_PSCReloadMode_Immediate);

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Timing;

TIM_OCInitStructure.TIM_Pulse = TIM3_CCR3_Val ;                           

TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;  

TIM_OC3Init(TIM3, &TIM_OCInitStructure); 

TIM_OC3PreloadConfig(TIM3, TIM_OCPreload_Disable);

//* time2 channel 4 PA3*/

TIM_TimeBaseStructure.TIM_Prescaler = 0;

      TIM_TimeBaseStructure.TIM_ClockDivision = 0;

      TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; 

    TIM_TimeBaseStructure.TIM_Period = 65536 - 1;

TIM_TimeBaseInit(TIM2,&TIM_TimeBaseStructure);

TIM_PrescalerConfig(TIM2, PrescalerValue2, TIM_PSCReloadMode_Immediate);

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle; 

TIM_OCInitStructure.TIM_Pulse = TIM2_CCR4_Val ;                           

TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;

TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;  

TIM_OC4Init(TIM2, &TIM_OCInitStructure); 

TIM_OC4PreloadConfig(TIM2, TIM_OCPreload_Disable);

TIM_SelectInputTrigger(TIM2, TIM_TS_ITR3);

              TIM_SelectSlaveMode(TIM2, TIM_SlaveMode_Trigger);

              

//* time4 channel 3 PB8 模式 输出比较触发   */

TIM_TimeBaseStructure.TIM_Prescaler = 0;

      TIM_TimeBaseStructure.TIM_ClockDivision = 0;

      TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; 

    TIM_TimeBaseStructure.TIM_Period = 65536 - 1;

    TIM_TimeBaseInit(TIM4,&TIM_TimeBaseStructure);

TIM_PrescalerConfig(TIM4, PrescalerValue, TIM_PSCReloadMode_Immediate);  

    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle; 

TIM_OCInitStructure.TIM_Pulse = TIM4_CCR3_Val ;             // 捕获比较值               

TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;   

TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;  

TIM_OC3Init(TIM4, &TIM_OCInitStructure); 

TIM_OC3PreloadConfig(TIM4, TIM_OCPreload_Disable); // 禁止预装值 

 

TIM_SelectOutputTrigger(TIM4, TIM_TRGOSource_Update);

TIM_SelectMasterSlaveMode(TIM4, TIM_MasterSlaveMode_Enable);

// 清除中断标志，避免开启中断就产生中断 

TIM_ClearITPendingBit(TIM2,TIM_IT_CC4); 

TIM_ITConfig(TIM2, TIM_IT_CC4, ENABLE);

TIM_ClearITPendingBit(TIM3,TIM_IT_CC3); 

TIM_ITConfig(TIM3, TIM_IT_CC3, ENABLE);

TIM_ClearITPendingBit(TIM4,TIM_IT_CC3); 

TIM_ITConfig(TIM4, TIM_IT_CC3, ENABLE);

TIM_Cmd(TIM4, ENABLE);

TIM_Cmd(TIM2, ENABLE);

TIM_Cmd(TIM3, ENABLE);

}

第一次使用STM32，使用定时器产生两个同步时钟信号，tim4输出100KHz信号正确，但tim2输出6.25KHz信号怎么也不对？

william_zeng

回复【楼主位】william_zeng:
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请原子指点......

正点原子

回复【2楼】william_zeng:
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TIM2输出现在是多少?

william_zeng

回复【3楼】正点原子:
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回复【3楼】正点原子:
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输出为200Hz左右

william_zeng

回复【4楼】william_zeng:
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回复【3楼】正点原子:

回复【2楼】william_zeng:
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TIM2输出现在是多少?

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回复【3楼】正点原子:
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但改变slave为门控或外部时钟1，输出就变为2Hz左右，很奇怪？

TIM_SelectSlaveMode(TIM2, TIM_SlaveMode_Trigger);
修改为 TIM_SelectSlaveMode(TIM2, TIM_SlaveMode_Gated);或 TIM_SelectSlaveMode(TIM2, TIM_SlaveMode_External1)

正点原子

回复【4楼】william_zeng:
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看你的时钟频率60M,你用的是什么芯片啊???
你试下不用slave模式,直接输出6.25Khz的方波,OK 不?

william_zeng

回复【6楼】正点原子:
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芯片为STM32F103ZET6,之前没有定时器同步，tim4输出100KHz，tim2输出为6.25KHz，都正常，只是应用中要求两个时钟同步，
将时钟级联后就遇到这个问题了。

william_zeng

回复【7楼】william_zeng:
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其中时钟配置为：
void RCC_Configuration(void)
{
/* 定义枚举类型变量 HSEStartUpStatus */
ErrorStatus HSEStartUpStatus;
   /* 复位系统时钟设置*/
   RCC_DeInit();
   /* 开启HSE*/
   RCC_HSEConfig(RCC_HSE_ON);
   /* 等待HSE起振并稳定*/
   HSEStartUpStatus = RCC_WaitForHSEStartUp();
/* 判断HSE起是否振成功，是则进入if()内部 */
   if(HSEStartUpStatus == SUCCESS)
   {
     /* 选择HCLK（AHB）时钟源为SYSCLK 1分频 */
     RCC_HCLKConfig(RCC_SYSCLK_Div1); 
     /* 选择PCLK2时钟源为 HCLK（AHB） 1分频 */
     RCC_PCLK2Config(RCC_HCLK_Div1); 
     /* 选择PCLK1时钟源为 HCLK（AHB） 2分频 */
     RCC_PCLK1Config(RCC_HCLK_Div2);
     /* 设置FLASH延时周期数为2 */
     FLASH_SetLatency(FLASH_Latency_2);
     /* 使能FLASH预取缓存 */
     FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);
     /* 选择锁相环（PLL）时钟源为HSE 1分频，倍频数为5，则PLL输出频率为 12MHz * 5 = 60MHz */
     RCC_PLLConfig(RCC_PLLSource_HSE_Div1, RCC_PLLMul_5);
     /* 使能PLL */ 
     RCC_PLLCmd(ENABLE);
     /* 等待PLL输出稳定 */
     while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET);
     /* 选择SYSCLK时钟源为PLL */
     RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);
     /* 等待PLL成为SYSCLK时钟源 */
     while(RCC_GetSYSCLKSource() != 0x08);
   } 

   /* 打开APB2总线上的GPIOA和GPIOB、UART时钟、复用功能时钟 */
   RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB| RCC_APB2Periph_GPIOD | RCC_APB2Periph_USART1 | RCC_APB2Periph_AFIO, ENABLE);

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2 | RCC_APB1Periph_TIM3 | RCC_APB1Periph_TIM4 , ENABLE);

//启动DMA时钟  
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE); 
}

william_zeng

回复【6楼】正点原子:
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不使用定时器同步，// time2  channel 4 60M/1200/4/2=6250Hz  Toggle  */  tim2输出6.25KHz频率信号正常

正点原子

哦,这个同步模式我还没研究过,呵呵.

william_zeng

回复【10楼】正点原子:
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问题找到,原来tim输出比较模式下不能给从tim提供时钟,将主tim修改为PWM模式，其余不变就ok了，谢谢原子。
应用手册中写到：In output compare mode, the update event UEV has no effect on ocxref and OCx output.

正点原子

回复【11楼】william_zeng:
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感谢分享.