第5章DSP的AD转换器祥解.ppt

* ADC转换结果缓冲寄存器: ADCRESULT0~15 寄存器ADCRESULTn中12位转换结果是左对齐的，即存放在16位寄存器的高12位。 * 5.6 ADC的C语言编程实例 例，A/D转换程序。采用双排序器和顺序采样模式, 排序器SEQ1对两个模拟输入通道ADCINA0和ADCINA1的电压信号进行自动转换。排序器采用事件管理器EVA(T1)的下溢中断标志作为触发启动信号。使用ADC模块的中断方式，每次排序结束(EOS)都产生中断。在中断服务程序中，读取模拟量的转换结果并存储到两个长度为1024的数组Voltage1和Voltage2中。 * #include DSP281x_Device.h // DSP281x Header file Include File interrupt void adc_isr(void); // Global variables used in this example 全局变量定义 Uint16 ConversionCount; //转换次数计数 Uint16 Voltage1[1024]; Uint16 Voltage2[1024]; main( ) { InitSysCtrl(); //初始化CPU DINT; //关中断 InitPieCtrl(); //初始化pie寄存器 IER = 0x0000; //禁止所有的中断 IFR = 0x0000; InitPieVectTable();//初始化pie中断向量表 EALLOW; // This is needed to write to EALLOW protected register * PieVectTable.ADCINT = adc_isr; EDIS; // This is needed to disable write to EALLOW protected registers AdcRegs.ADCTRL1.bit.RESET = 1; // Reset the ADC module asm( RPT #10 || NOP); // Wait 12-cycles for ADC reset to take effect AdcRegs.ADCTRL3.all = 0x00C8; // first power-up ref and bandgap circuits AdcRegs.ADCTRL3.bit.ADCBGRFDN = 0x3; // Power up bandgap/ref circuitry AdcRegs.ADCTRL3.bit.ADCPWDN = 1; // Power up rest of ADC // Enable ADCINT in PIE PieCtrlRegs.PIEIER1.bit.INTx6 = 1; IER |= M_INT1; // Enable CPU Interrupt 1 EINT; // Enable Global interrupt INTM ERTM; // Enable Global realtime interrupt DBGM LoopCount = 0; ConversionCount = 0; // Configure ADC AdcRegs.ADCMAXCONV.all = 0x0001; // Setup 2 convs on SEQ1 AdcRegs.ADCCHSELSEQ1.bit.CONV00 = 0x0; // Setup ADCINA0 as 1st SEQ1 AdcRegs.ADCCHSELSEQ1.bit.CONV01 = 0x1; // Setup ADCINA1 as 2nd SEQ1 * AdcRegs.ADCTRL2.bit.EVA_SOC_SEQ1 = 1; // Enable EVASOC to start SEQ1 AdcRegs.ADCTRL2.bit.INT_ENA_SEQ1 = 1; // Enable SEQ1 interrupt (every EOS) // Configure EVA // Assumes EVA Clock is already enabled in InitSysCtrl(); EvaRegs.T1CMPR = 0x0080;