MK02FN64VFM10的ADC用PDB触发

逍遥随风 · 发表于 2015-12-2 14:00:02

各位大侠：
         小弟刚使用飞思卡尔单片机MK02FN64VFM10。目前使用PDB触发ADC采样，遇到了不能触发转换的问题，代码如下

ADC0_CFG1 |=0x0000000C;//16Î»ADC
ADC0_CFG2 |=0x00000004;//¸ßËÙ×ª»¯
ADC0_SC1A=0x00;
ADC0_SC1A  |=0x00000009;//ADC9£¬µ¥¶ËÄ£Ê½
ADC0_SC2 |=0x00000004;//Ó²¼þ´¥·¢×ª»¯
ADC0_SC3 |=0x0000000E;//Á¬Ðø×ª»»

   SIM_SCGC6 |= SIM_SCGC6_PDB_MASK ;  // 使能时钟
//两个ADC模块,配置他们的触发方式（软硬触发？）
SIM_SOPT7 &= ~(SIM_SOPT7_ADC1ALTTRGEN_MASK  | // 由于ADC1可以硬件触发，也可以软件触发，这里选择PDB（软件）触发
            SIM_SOPT7_ADC1PRETRGSEL_MASK | // 选择预触发器A
            SIM_SOPT7_ADC0ALTTRGEN_MASK  | // selects PDB not ALT trigger
            SIM_SOPT7_ADC0ALTTRGEN_MASK) ;
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
SIM_SOPT7 = SIM_SOPT7_ADC0TRGSEL(0);    // 选择在PDB模式下，ADC的触发的输入命令源，这里是PDB的外部管脚；103或者111
                                          // PDB external pin input trigger for ADC
SIM_SOPT7 = SIM_SOPT7_ADC1TRGSEL(0);    // same for both ADCs
// 配置频率，使能pdb，以及选择pdb的中断触发源，
PDB0_SC =  PDB_SC_CONT_MASK    //配置成是连续触发还是单发的
      | PDB_SC_PDBEN_MASK    // PDB enabled
      | PDB_SC_PDBIE_MASK    // PDB Interrupt Enable
      | PDB_SC_PRESCALER(0x5)  // 配置分频
      | PDB_SC_TRGSEL(0xf)    // 中断源选择，这里是软件中断，就是配置触发中断的方式
      | PDB_SC_MULT(2);       // Multiplication factor 20 for the prescale divider for the counter clock
                              // the software trigger, PDB_SC_SWTRIG_MASK is not triggered at this time.
PDB0_IDLY = 0x0000; // 软件中断发生时刻，其实也是读取转换值时刻
PDB0_MOD = 0xffff; // 总周期
// channel 0 pretrigger 0 and 1 enabled and delayed
PDB0_CH0C1 = PDB_C1_EN(0x01) //使能通道0预触发模式
         | PDB_C1_TOS(0x01) //选择某一PDB通道为ADC的预触发输出
         | PDB_C1_EN(0x02)
         | PDB_C1_TOS(0x02) ;
PDB0_CH0DLY0 = ADC0_DLYA ; //这里配置0时刻开始，就会去做adc的通道之类的链接
PDB0_CH0DLY1 = ADC0_DLYB ; //到了1时刻就开启ADC了，完成了一次数据转换了，在中断时候提出数据

/ channel 1 pretrigger 0 and 1 enabled and delayed
PDB0_CH1C1 = PDB_C1_EN(0x01)
         | PDB_C1_TOS(0x01)
         | PDB_C1_EN(0x02)
         | PDB_C1_TOS(0x02) ;
PDB0_CH1DLY0 = ADC1_DLYA ;
PDB0_CH1DLY1 = ADC1_DLYB ;
PDB0_SC =  PDB_SC_CONT_MASK       // Contintuous, rather than one-shot, mode
      | PDB_SC_PDBEN_MASK    // PDB enabled
      | PDB_SC_PDBIE_MASK    // PDB Interrupt Enable
      | PDB_SC_PRESCALER(0x5) // Slow down the period of the PDB for testing
      | PDB_SC_TRGSEL(0xf)    // Trigger source is Software Trigger to be invoked in this file
      | PDB_SC_MULT(2)       // Multiplication factor 20 for the prescale divider for the counter clock
      | PDB_SC_LDOK_MASK;    // Need to ok the loading or it will not load certain regsiters!
不知道是什么问题，是不是配置PDB的触发不对还是ADC触发形式选择不对？

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