我在STM32F103R6T6上用TIM1的PWM 引脚是PA.8 PA.9
代码如下：
///////////////////////////////////////////////////
TIM1_CH1_PWM_RmapInit(99,14);
/////////////////////////////////////////////////////
//arr£º×Ô¶¯ÖØ×°Öµ
//psc£ºÊ±ÖÓÔ¤·ÖƵÊý
//¶¨Ê±Æ÷1 ·¢2·PWM²¨
void TIM1_CH1_PWM_RmapInit(u16 arr,u16 psc)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
TIM_DeInit(TIM1);//³õʼ»¯TIM1¼Ä´æÆ÷
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1 | RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE); //ʹÄÜGPIOÍâÉèºÍAFIO¸´Óù¦ÄÜÄ£¿éʱÖÓ
//ÉèÖøÃÒý½ÅΪ¸´ÓÃÊä³ö¹¦ÄÜ,Êä³öTIM1 CH1 2 µÄPWMÂö³å²¨ÐÎ GPIOA.8 GPIOA.9
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8|GPIO_Pin_9; //TIM1_CH1 CH2
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //¸´ÓÃÍÆÍìÊä³ö
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);//³õʼ»¯GPIO
//³õʼ»¯TIM1
TIM_TimeBaseStructure.TIM_Period = arr; //
TIM_TimeBaseStructure.TIM_Prescaler =psc; //
TIM_TimeBaseStructure.TIM_ClockDivision = 0; //
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Down; //
TIM_TimeBaseStructure.TIM_RepetitionCounter = 0x0;
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Disable;
TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Reset ;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
TIM_OC1Init(TIM1, &TIM_OCInitStructure);
TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable);
TIM_SetCompare1(TIM1,0);
//³õʼ»¯TIM1 Channel2 PWMģʽ
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Disable;
TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Reset ;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
TIM_OC2Init(TIM1, &TIM_OCInitStructure);
TIM_OC2PreloadConfig(TIM1, TIM_OCPreload_Enable);
TIM_SetCompare2(TIM1,0);
TIM_ARRPreloadConfig(TIM1, ENABLE);
TIM_Cmd(TIM1, ENABLE); //
TIM_CtrlPWMOutputs(TIM1, ENABLE);//
}
我的理解现在输出的一个低电平，但是事实上输出的是周期是20us 宽度是200ns的高电平？
用其他的TIM做PWM 就是输出一个低电平，唯独TIM1出现上述问题。
向各位请教这是什么原因？ |
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