PA8-----------------TIM1_CH1
PA0--------------TIM2_CH1
上面的是PA8输出,下面的是PA0输出。
完成的功能:PA8和PA0分别输出PWM波,单PA8为低电平的时候PA0才输出PWM波
否则不输出,这个时候PA0可能输出高,也可能输出低,这个暂时不知道怎么解决。。
稍微解释一下代码:
1.TIM1设置为主模式,把PWM的参考电平OC1REF作为TRGO触发输出。
TIM_SelectMasterSlaveMode(TIM1, TIM_MasterSlaveMode_Enable);
TIM_SelectOutputTrigger(TIM1, TIM_TRGOSource_OC1Ref);
2.将TIM2设置为从模式的门控模式,将TIM1的TRG0作为触发输入,控制定时器的开启和关闭。(PS:门控模式:当触发输入(TRGI)为高时,计数器的时钟开启。一旦触发输入变为低,则计数器停止(但不复位)。计数器的启动和停止都是受控的。)
TIM_SelectSlaveMode(TIM2, TIM_SlaveMode_Gated);
TIM_SelectInputTrigger(TIM2, TIM_TS_ITR0);
参考代码如下:
//定时器主从模式初始化
void TIM_MasterSlaveModeInit(void){
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
//打开时钟
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2 , ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1 , ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
//配置TIM1定时器周期
TIM_TimeBaseStructure.TIM_Period = 100;
TIM_TimeBaseStructure.TIM_Prescaler = 719;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);
//主模式 TIM1_CH1 PWM配置
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = 50;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
TIM_OC1Init(TIM1, &TIM_OCInitStructure);
//选择主从模式
TIM_SelectMasterSlaveMode(TIM1, TIM_MasterSlaveMode_Enable);
//主定时器触发输出配置
TIM_SelectOutputTrigger(TIM1, TIM_TRGOSource_OC1Ref); //选择PWM 参考电压OC1REF为触发输出
//配置TIM2定时器周期
TIM_TimeBaseStructure.TIM_Period = 10;
TIM_TimeBaseStructure.TIM_Prescaler = 719;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
//从定时器TIM2 PWM输出配置
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = 5;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
TIM_OC1Init(TIM2, &TIM_OCInitStructure);
//从模式选择
TIM_SelectSlaveMode(TIM2, TIM_SlaveMode_Gated); //门控模式
TIM_SelectInputTrigger(TIM2, TIM_TS_ITR0); //定时器1 的Trigger 0做为触发输入
//使能定时器
TIM_Cmd(TIM2, ENABLE);
TIM_Cmd(TIM1, ENABLE);
TIM_CtrlPWMOutputs(TIM1, ENABLE);
}