要求得到下列波形，死区时间1us,CH1和CH1之间的相位差事3us,频率50HZ。 1，To get TIM1 counter clock at 72MHz,the prescaler is computer as follows: Prescaler = (TIM1CLK / TIM1 counter clock) - 1 To objective is to genterate PWM signal at 50KHz: -TIM1_Priod = (SystemCoreClock / 50000) - 1 To get TIM1 output clock at 50KHz , the period (ARR) is computed as follows : ARR = (TIM1 counter clock / TIM1 output clock) - 1 The Two Duty cycles are computed as the following description : TIM1 Channel1 duty cycle = (TIM1_CCR1 / TIM1_ARR)*100 = 50% TIM1 Channel2 duty cycle = (TIM1_CCR1 / TIM1_ARR)*100 = 50% The Timer pulse is calculated as follows : TIM1_CCRx = (DutyCycle * TIM1_ARR) / 100 2，死区时间deadtime的计算方法 UTG[7:0]:死区发生器装置，这些位定义了插入互补输出之间的死区持续时间，假设DT标示其持续时 间： DTG[7:0] = 0xx => DT = DTG[7:0]× Tdtg , Tdtg = TDTS ; DTG[7:0] = 10x => DT = (64 + DTG[5:0])× Tdtg , Tdtg = 2×TDTS ; DTG[7:0] = 110 => DT = (32 + DTG[4:0])× Tdtg , Tdtg = 8×TDTS ; DTG[7:0] = 111 => DT = (32 + DTG[4:0])× Tdtg , Tdtg = 16×TDTS ; 例子：若TDTS = 13.89ns(72MHz),可能的死区时间位： 0到1764ns，若步长13.89ns； 1777.9ns到3528.88ns； 3555.84ns到7000.56ns； 7111.68ns到14001.12ns； 如果 deadtime=1us，落在区间0到1764ns，所以公式选择& amp;nbsp;DTG[7:0] = 0xx => DT = DTG[7:0]× Tdtg , Tdtg = TDTS ; 1us = x 13.89ns，x=72，DTG[7:0]=0x72。假设是用第二个公式得到的30则DTG[5：0]=0b11110，加上DTG的前两位就是 DTG[7： 0]=0b1011110=0x5E； 3，Configure the break feature,active at High level,and using the automatic output enable feature 4，Use the Locking parameters level1 5，要求这两个通道的波形不对齐，那么TIM1_CCMR1的OC1M[2：0]必须设定为011，即 TIM_OCInitStructure.TIM_OCMode=TIM_OCMode_Toggle;这样ARR走两趟才是一个周期。 6，要求PWM输出频率为50KHz。所以ARR=(72MHz/100000)-1=719 因为ARR加1的时间为（1/72MHz）s，则(1/72MHz)X=3us。X=216即CCR1、 CCR2之间相隔216时，PWM的相位差是3us。 程序如下：< /div>void TIM1_PWM_DeadtimeInit(uint16_t arr,uint16_t psc,uint16_t ccr1,uint16_t ccr2,uint16_t deadtime) { GPIO_InitTypeDef GPIO_InitStructure; TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; TIM_OCInitTypeDef TIM_OCInitStructure; TIM_BDTRInitTypeDef TIM_BDTRInitStructure; RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB,ENABLE); RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1,ENABLE); /************************************************* *采用寄存器模式 *TIM1的互补PWM，没有使用重映像，CH1-PA8，CH1-PB13< /div> GPIOA->CRH&=0XFFFFFFF0; //PA8输出 GPIOA->CRH|=0X0000000B; //复用功能输出 推挽式 GPIOA->ODR|=3<<8; GPIOB->CRH&=0XFF0FFFFF; //PB13输出 GPIOB->CRH|=0X00B00000; //复用功能输出 推挽式 GPIOB->ODR|=3<<13; ***************************************************/ /**************************************************/ /*TIM1的互补PWM，没有使用重映像，CH1-PA8，CH1-PB13*/< /div> GPIO_InitStructure.GPIO_Pin=GPIO_Pin_8 | GPIO_Pin_9; 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_13 | GPIO_Pin_14; GPIO_InitStructure.GPIO_Mode=GPIO_Mode_AF_PP; GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz; GPIO_Init(GPIOB,&GPIO_InitStructure); /*************************************************/ /************************************************* *TIM1的互补PWM,使用完全重映射，CH1-PE9，CH1N-PE8*< /div> GPIO_PinRemapConfig(GPIO_FullRemap_TIM1,ENABLE);//使用 AFIO_MARP的位7:6=11,完全重映像TIM1_CH1到PE9，TIM1_CH1N到PE8 <div& gt; GPIO_InitStructure.GPIO_Pin=GPIO_Pin_8|GPIO_Pin_9; GPIO_InitStructure.GPIO_Mode=GPIO_Mode_AF_PP; GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz; GPIO_Init(GPIOE,&GPIO_InitStructure); *************************************************/ /**问题是当使用不完全重映射的互补PWM出现问题****< /div> GPIO_PinRemapConfig(GPIO_PartialRemap_TIM1,ENABLE);//使用 AFIO_MARP的位7:6=01,部分重映像TIM1_CH1到PA8，TIM1_CH1N到PA7 <div& gt; GPIO_InitStructure.GPIO_Pin=GPIO_Pin_7 | GPIO_Pin_8; GPIO_InitStructure.GPIO_Mode=GPIO_Mode_AF_PP; GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz; GPIO_Init(GPIOA,&GPIO_InitStructure); ************************************************/ //TIM1 TIM_TimeBaseStructure.TIM_Period=arr; TIM_TimeBaseStructure.TIM_Prescaler=psc; TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up; TIM_TimeBaseStructure.TIM_ClockDivision=0; TIM_TimeBaseStructure.TIM_RepetitionCounter = 0; TIM_TimeBaseInit(TIM1,&TIM_TimeBaseStructure); TIM_OCInitStructure.TIM_OCMode=TIM_OCMode_Toggle;//翻转，当 TIMx_CCR1=TIMx_CNT时，翻转OC1REF的电平 TIM_OCInitStructure.TIM_Pulse=ccr1; TIM_OCInitStructure.TIM_OCPolarity=TIM_OCPolarity_High; //CCER的CC1P，输入/捕获输出极性 TIM_OCInitStructure.TIM_OCNPolarity=TIM_OCPolarity_High; TIM_OCInitStructure.TIM_OutputState=TIM_OutputState_Enable; //CER的CC1N，输入/捕获输出使能 TIM_OCInitStructure.TIM_OutputNState=TIM_OutputNState_Enable; TIM_OCInitStructure.TIM_OCIdleState=TIM_OCIdleState_Reset; //OIS1位 TIM_OCInitStructure.TIM_OCNIdleState=TIM_OCNIdleState_Reset; //CR2的OIS1N位，当MOE位0时，输出空闲状态位OIS1N. TIM_OC1Init(TIM1,&TIM_OCInitStructure); TIM_OCInitStructure.TIM_Pulse=ccr2;//316 TIM_OC2Init(TIM1,&TIM_OCInitStructure); TIM_BDTRInitStructure.TIM_OSSRState=TIM_OSSRState_Disable; //OSSR:运行模式下“关闭状态”选择(Off-state selection for Run mode) TIM_BDTRInitStructure.TIM_OSSIState=TIM_OSSIState_Disable; //OSSI:空闲模式下“关闭状态”选择 (Off-state selection for Idle mode) TIM_BDTRInitStructure.TIM_LOCKLevel=TIM_LOCKLevel_1;//锁定设 置，级别为1， TIM_BDTRInitStructure.TIM_DeadTime=deadtime;//死区延时时间< /div> TIM_BDTRInitStructure.TIM_Break=TIM_Break_Disable;//禁止刹车输 入 TIM_BDTRInitStructure.TIM_BreakPolarity=TIM_BreakPolarity_Low; //刹车输入极性 TIM_BDTRInitStructure.TIM_AutomaticOutput=TIM_AutomaticOutput_Enable; //自动输出使能 TIM_BDTRConfig(TIM1,&TIM_BDTRInitStructure); TIM_CtrlPWMOutputs(TIM1,ENABLE);//BDTR的MOE位< /div> TIM_OC1PreloadConfig(TIM1,TIM_OCPreload_Enable);//CCMR1 TIM_OC2PreloadConfig(TIM1,TIM_OCPreload_Enable);//CCMR1 TIM_ARRPreloadConfig(TIM1,ENABLE);//CR1 TIM_Cmd(TIM1,ENABLE);//CR1 }< /div> 主函数调用 void main(void) { ...... TIM1_PWM_DeadtimeInit(719,0,100,316,72)//uint16_t arr,uint16_t psc,uint16_t ccr1,uint16_t ccr2,uint16_t deadtime } |
