请问使用自带的例子，6步产生PWM，怎么测量不到任何波形。

只看该作者 · 2009-10-29 22:19

本帖最后由 ZUI135 于 2009-10-29 22:24 编辑

我现在需要使用tim1来产生6步的PWM波
下面是例子的初始化代码：
         -----------------------------------------------
         | Step1 | Step2 | Step3 | Step4 | Step5 | Step6 |
----------------------------------------------------------
  |Channel1  | 1 | 0 | 0 | 0 | 0 | 1 |
----------------------------------------------------------
  |Channel1N | 0 | 0 | 1 | 1 | 0 | 0 |
----------------------------------------------------------
  |Channel2  | 0 | 0 | 0 | 1 | 1 | 0 |
----------------------------------------------------------
  |Channel2N | 1 | 1 | 0 | 0 | 0 | 0 |
----------------------------------------------------------
  |Channel3  | 0 | 1 | 1 | 0 | 0 | 0 |
----------------------------------------------------------
  |Channel3N | 0 | 0 | 0 | 0 | 1 | 1 |
----------------------------------------------------------
  -----------------------------------------------------------------------------*/
  /* Time Base configuration */
  TIM_TimeBaseStructure.TIM_Prescaler = 0;
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
  TIM_TimeBaseStructure.TIM_Period = 4095;
  TIM_TimeBaseStructure.TIM_ClockDivision = 0;
  TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
  TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);
  /* Channel 1, 2,3 and 4 Configuration in PWM mode */
  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Timing;
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;
  TIM_OCInitStructure.TIM_Pulse = 1000;
  TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
  TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High;
  TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
  TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCNIdleState_Set;
  TIM_OC1Init(TIM1, &TIM_OCInitStructure);
  TIM_OCInitStructure.TIM_Pulse = 2000;
  TIM_OC2Init(TIM1, &TIM_OCInitStructure);
  TIM_OCInitStructure.TIM_Pulse = 3250;
  TIM_OC3Init(TIM1, &TIM_OCInitStructure);
  /* Automatic Output enable, Break, dead time and lock configuration*/
  TIM_BDTRInitStructure.TIM_OSSRState = TIM_OSSRState_Enable;
  TIM_BDTRInitStructure.TIM_OSSIState = TIM_OSSIState_Enable;
  TIM_BDTRInitStructure.TIM_LOCKLevel = TIM_LOCKLevel_OFF;
  TIM_BDTRInitStructure.TIM_DeadTime = 1;
  TIM_BDTRInitStructure.TIM_Break = TIM_Break_Enable;
  TIM_BDTRInitStructure.TIM_BreakPolarity = TIM_BreakPolarity_High;
  TIM_BDTRInitStructure.TIM_AutomaticOutput = TIM_AutomaticOutput_Enable;
  TIM_BDTRConfig(TIM1, &TIM_BDTRInitStructure);
  TIM_CCPreloadControl(TIM1, ENABLE);
  TIM_ITConfig(TIM1, TIM_IT_COM, ENABLE);
  /* TIM1 counter enable */
  TIM_Cmd(TIM1, ENABLE);
  /* Main Output Enable */
  TIM_CtrlPWMOutputs(TIM1, ENABLE);SysTick触发COM中断，NVIC和RCC都有开，程序单步运行和全速运行测量，都无法测量到波形输出，万用表也测量不到，全部是0.
这个是怎么回事？？？？帮帮我