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下面是使用高级定时器TIM8输出四路PWM波的程序,经示波器观察后可以得到想要波形。
void TIM8_PWM_Init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM8, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC, ENABLE);
//éèÖøÃòy½ÅÎa¸′óÃêä3ö1|Äü,êä3öTIM1 CH1μÄ WMÂö3å2¨DÎ
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6|GPIO_Pin_7|GPIO_Pin_8|GPIO_Pin_9; //TIM4_CH1~4
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOC, &GPIO_InitStructure);
//////////////////////////
//////////////////////////
TIM_TimeBaseStructure.TIM_Period = 719; //
TIM_TimeBaseStructure.TIM_Prescaler =0; //
TIM_TimeBaseStructure.TIM_ClockDivision = 0; //
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //
TIM_TimeBaseInit(TIM8, &TIM_TimeBaseStructure); //
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //
TIM_OCInitStructure.TIM_Pulse = 0; //
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low; //
TIM_OC1Init(TIM8, &TIM_OCInitStructure); //
TIM_OC2Init(TIM8, &TIM_OCInitStructure);
TIM_OC3Init(TIM8, &TIM_OCInitStructure);
TIM_OC4Init(TIM8, &TIM_OCInitStructure);
TIM_CtrlPWMOutputs(TIM8,ENABLE);
TIM_OC1PreloadConfig(TIM8, TIM_OCPreload_Enable); //
TIM_OC2PreloadConfig(TIM8, TIM_OCPreload_Enable);
TIM_OC3PreloadConfig(TIM8, TIM_OCPreload_Enable);
TIM_OC4PreloadConfig(TIM8, TIM_OCPreload_Enable);
TIM_ARRPreloadConfig(TIM8, ENABLE); //
TIM_Cmd(TIM8, ENABLE); //
}
(复制过来后的注释都是乱码,就删了)
但是,我用通用定时器TIM4写了类似的程序,目的也是输出四路PWM波,但结果根本没有输出。
程序如下:
void TIM4_PWM_Init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
RCC_APB2PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);//
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE); //
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6|GPIO_Pin_7|GPIO_Pin_8|GPIO_Pin_9; //TIM4_CH1~4
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //¸′óÃíÆíìêä3ö
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &GPIO_InitStructure);
//////////////////////////
//////////////////////////
TIM_TimeBaseStructure.TIM_Period = 719; //
TIM_TimeBaseStructure.TIM_Prescaler =0; //
TIM_TimeBaseStructure.TIM_ClockDivision = 0; //
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //
TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure); //
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //
TIM_OCInitStructure.TIM_Pulse = 0; //
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low; //
TIM_OC1Init(TIM4, &TIM_OCInitStructure); //
TIM_OC2Init(TIM4, &TIM_OCInitStructure);
TIM_OC3Init(TIM4, &TIM_OCInitStructure);
TIM_OC4Init(TIM4, &TIM_OCInitStructure);
TIM_CtrlPWMOutputs(TIM4,ENABLE); //
TIM_OC1PreloadConfig(TIM4, TIM_OCPreload_Enable); //
TIM_OC2PreloadConfig(TIM4, TIM_OCPreload_Enable);
TIM_OC3PreloadConfig(TIM4, TIM_OCPreload_Enable);
TIM_OC4PreloadConfig(TIM4, TIM_OCPreload_Enable);
TIM_ARRPreloadConfig(TIM4, ENABLE);
TIM_Cmd(TIM4, ENABLE);
}
问,产生这样的原因是我程序写错了,还是仅仅是高级定时器和通用定时器的区别?
求大神~~~
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最佳答案
查看完整内容[请看2#楼]
2个地方改改:
TIM4在APB1上 用这个RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE); 不是RCC_APB2PeriphClockCmd;
CCRx 改为不为0且小于719的值,TIM_OCInitStructure.TIM_Pulse = 200;
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