金牌会员
 
- 积分
- 1790
- 金钱
- 1790
- 注册时间
- 2018-3-26
- 在线时间
- 294 小时
|
29金钱
用的TIM1的PWM输出模式,问题就是标题,现在是用的103,不知道407可不可以,但是407没发软件仿真看不出来。
调试时,100KHz还能稳定输出,大于100KHz之后就有些问题了,具体在哪个数值变化没有精确测试,反正1MHz输出不出来。
是不是中断响应时间不够,导致的输出上不去呢? 以下附上代码,各位大神帮忙分析分析。。。
这是TIM1 的初始化,主要配置了4个通道输出。
- static void TIM1_GPIO_Config(void)
- {
- GPIO_InitTypeDef GPIO_InitStructure;
- /* GPIOA and GPIOB clock enable */
- RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
- // GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13 ;//| GPIO_Pin_14 | GPIO_Pin_15;
- // GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
- // GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
- // GPIO_Init(GPIOB, &GPIO_InitStructure);
-
- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9 | GPIO_Pin_10 | GPIO_Pin_11;
- GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
- GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
- GPIO_Init(GPIOA, &GPIO_InitStructure);
- }
- /*配置TIM1输出的PWM信号的模式,如周期、极性、占空比 */
- static void TIM1_Mode_Config(u32 arr,u32 psc)
- {
- TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
- TIM_OCInitTypeDef TIM_OCInitStructure;
- NVIC_InitTypeDef NVIC_InitStructure;
-
- /* TIM1 clock enable */
- RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);
-
- NVIC_InitStructure.NVIC_IRQChannel=TIM1_CC_IRQn;
- NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=0;
- NVIC_InitStructure.NVIC_IRQChannelSubPriority=1;
- NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;
- NVIC_Init(&NVIC_InitStructure);
-
- /* Time base configuration */
- TIM_TimeBaseStructure.TIM_Period = psc; //2M/1000 = 1K
- TIM_TimeBaseStructure.TIM_Prescaler = arr; //72M/(35+1) = 2M
- TIM_TimeBaseStructure.TIM_ClockDivision = 0;
- TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
- TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);
- /* PWM1 Mode configuration: Channel1 */
- TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle;
- TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
- TIM_OCInitStructure.TIM_Pulse = CCR1_Val;//(psc+1)/2;
- TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
- TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
- TIM_OC1Init(TIM1, &TIM_OCInitStructure);
- // TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable);
- ///*
- // PWM1 Mode configuration: Channel2
- TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle;
- TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
- TIM_OCInitStructure.TIM_Pulse = CCR2_Val;//(psc+1)/2;
- TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
- TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
-
- TIM_OC2Init(TIM1, &TIM_OCInitStructure);
- // TIM_OC2PreloadConfig(TIM1, TIM_OCPreload_Enable);
- // PWM1 Mode configuration: Channel3
- TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle;
- TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
- TIM_OCInitStructure.TIM_Pulse = CCR3_Val;//(psc+1)/2;
- TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
- TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
-
- TIM_OC3Init(TIM1, &TIM_OCInitStructure);
- // TIM_OC3PreloadConfig(TIM1, TIM_OCPreload_Enable);
- // PWM1 Mode configuration: Channel1
- TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle;
- TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
- TIM_OCInitStructure.TIM_Pulse = CCR4_Val;//(psc+1)/2;
- TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
- TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
- TIM_OC4Init(TIM1, &TIM_OCInitStructure);
- // TIM_OC4PreloadConfig(TIM1, TIM_OCPreload_Enable);
- //*/
- TIM_ARRPreloadConfig(TIM1, ENABLE);
- /* TIM1 enable counter */
- TIM_Cmd(TIM1, ENABLE);
- TIM_ITConfig(TIM1, TIM_IT_CC1 | TIM_IT_CC2 | TIM_IT_CC3 | TIM_IT_CC4, ENABLE);
- TIM_CtrlPWMOutputs(TIM1, ENABLE);
- }
复制代码
这是中断处理,中间有一些不懂参考的网上。这个里面解答了我一些疑惑,可以参考下 https://blog.csdn.net/hes_c/article/details/88897149
- void TIM1_CC_IRQHandler(void)
- {
- if (TIM_GetITStatus(TIM1, TIM_IT_CC1) != RESET)
- {
- TIM_ClearITPendingBit(TIM1, TIM_IT_CC1);
- capture = TIM_GetCapture1(TIM1);
- TIM_SetCompare1(TIM1, capture + CCR1_Val);
- }
-
- if (TIM_GetITStatus(TIM1, TIM_IT_CC2) != RESET)
- {
- TIM_ClearITPendingBit(TIM1, TIM_IT_CC2);
- capture = TIM_GetCapture2(TIM1);
- TIM_SetCompare2(TIM1, capture + CCR2_Val);
- }
-
- if (TIM_GetITStatus(TIM1, TIM_IT_CC3) != RESET)
- {
- TIM_ClearITPendingBit(TIM1, TIM_IT_CC3);
- capture = TIM_GetCapture3(TIM1);
- TIM_SetCompare3(TIM1, capture + CCR3_Val);
- }
-
- if (TIM_GetITStatus(TIM1, TIM_IT_CC4) != RESET)
- {
- TIM_ClearITPendingBit(TIM1, TIM_IT_CC4);
- capture = TIM_GetCapture4(TIM1);
- TIM_SetCompare4(TIM1, capture + CCR4_Val);
- }
- }
复制代码
再就是主函数的调用。。。
- u16 capture = 0;
- vu16 CCR1_Val = 0;
- vu16 CCR2_Val = 0;
- vu16 CCR3_Val = 0;
- vu16 CCR4_Val = 0;
- int main(void)
- {
- /* 定时器初始化 TIMx_PWM_Init(u32 arr,u32 psc)*/
- //计算公式 系统时钟 72M/(arr+1) = 计数器时钟
- // 计数器时钟 / (psc+1) = 频率
- TIM1_PWM_Init(1-1 ,65536 - 1); //1M
- CCR1_Val = 3600; //10KHz
- CCR2_Val = 360; //100KHz
- CCR3_Val = 270;
- CCR4_Val = 36; //1MHz
- while(1)
- {
- }
- }
复制代码
以下是keil自带的仿真结果,CCR4_Val 输出的就不是理想的频率了。
可以看到第二张下面的时间,确定波形1 和 波形2的频率为 10KHz 和 100KHz,
到下面1MHz 就输出不了了。。。是有啥没注意的地方吗,求大神指导。。。
|
最佳答案
查看完整内容[请看2#楼]
换不同定时器才可以,你这种输出比较模式,不适合频率高的应用,因为MCU的中断处理是需要时间的,很难处理1Mhz以上的中断。
|