初始化程序
#if (CPU_FRQ_150MHZ) // Default - 150 MHz SYSCLKOUT
#define ADC_MODCLK 0x3 // HSPCLK = SYSCLKOUT/2*ADC_MODCLK2 = 150/(2*3) = 25.0 MHz
#endif
#if (CPU_FRQ_100MHZ)
#define ADC_MODCLK 0x2 // HSPCLK = SYSCLKOUT/2*ADC_MODCLK2 = 100/(2*2) = 25.0 MHz
#endif
void Init_ADC(void)
{
uint16_t tmp = 0;
EALLOW;
SysCtrlRegs.HISPCP.all = ADC_MODCLK; // HSPCLK = SYSCLKOUT/ADC_MODCLK
EDIS;
AdcRegs.ADCTRL3.all = 0x00E0; // Power up bandgap/reference/ADC circuits
tmp = 5000;
while(tmp--); // 等待ADC稳定
//以下开始设置ADC的控制寄存器、转换通道选择寄存器等
AdcRegs.ADCST.all = 0x30; //首先清除中断标志位
AdcRegs.ADCOFFTRIM.all = 0;
AdcRegs.ADCTRL3.all = 0x0E2;
//bit7~6:ADCBGRFDN[1:0]:adc 缝隙上电，3上电
//bit5：ADCPWDN：adc 模块上电，set1 上电
//bit1~4:ADCCLKPS=1
// bit0:SMODE_SEL =0 :set 0 顺序采样； set1 ：同步采样
// 0 = [ADCCLK = HSPCLK/(CPS+1)], 1 = [ADCCLK = HSPCLK/2*(1)(CPS+1)]; HSPCLK 默认情况下 = CPUSYSCLK/2;
//ADC module clock = HSPCLK/2*ADC_CKPS = 25.0MHz/(1*2) = 12.5MHz
//设置为顺序采样模式 0 = 连续采样方式 1 = 并发采样方式
AdcRegs.ADCTRL1.all = 0x0F50;
/*bit13~12：SUSMOD=0;
bit11~8：ACQ_PS =F :16 ADC clocks;
bit7: CPS =0时钟预分频1
bit6: CONT_RUN=1；//设置为启停模式 0 = 启停模式，1 = 连续转换模式
bit5:SEQ_OVRD = 0
bit4:SEQ_CASC =1//级联模式 0 = 双序列发生器方式， 1 = 级联模式
*/
//AdcRegs.ADCTRL1.bit.CONT_RUN = 1;
AdcRegs.ADCTRL2.all = 0x0000;
AdcRegs.ADCMAXCONV.all = 0x0F; //最大转换16通道
AdcRegs.ADCCHSELSEQ1.bit.CONV00 = 0; // ADCINA0 & ADCINB0
AdcRegs.ADCCHSELSEQ1.bit.CONV01 = 1; // ADCINA1 & ADCINB1
AdcRegs.ADCCHSELSEQ1.bit.CONV02 = 2; // ADCINA2 & ADCINB2
AdcRegs.ADCCHSELSEQ1.bit.CONV03 = 3; // ADCINA3 & ADCINB3
AdcRegs.ADCCHSELSEQ2.bit.CONV04 = 4; // ADCINA4 & ADCINB4
AdcRegs.ADCCHSELSEQ2.bit.CONV05 = 5; // ADCINA5 & ADCINB5
AdcRegs.ADCCHSELSEQ2.bit.CONV06 = 6; // ADCINA6 & ADCINB6
AdcRegs.ADCCHSELSEQ2.bit.CONV07 = 7; // ADCINA7 & ADCINB7
AdcRegs.ADCCHSELSEQ3.bit.CONV08 = 8; // ADCINA8 & ADCINB8
AdcRegs.ADCCHSELSEQ3.bit.CONV09 = 9; // ADCINA9 & ADCINB9
AdcRegs.ADCCHSELSEQ3.bit.CONV10 = 10; // ADCINA10 & ADCINB10
AdcRegs.ADCCHSELSEQ3.bit.CONV11 = 11; // ADCINA11 & ADCINB11
AdcRegs.ADCCHSELSEQ4.bit.CONV12 = 12; // ADCINA12 & ADCINB12
AdcRegs.ADCCHSELSEQ4.bit.CONV13 = 13; // ADCINA13 & ADCINB13
AdcRegs.ADCCHSELSEQ4.bit.CONV14 = 14; // ADCINA14 & ADCINB14
AdcRegs.ADCCHSELSEQ4.bit.CONV15 = 15; // ADCINA15 & ADCINB15
}
系统时钟用的是150M
读取结果的函数
void Test_Ai_Handle(Ubyte *paramData)
{
uint16_t i = 0;
uint16_t value[16];
uint16_t chan = 0;
float tmp = 0;
uint16_t delay_tmp = 0;
chan = paramData[0];
memset((void *)value, 0, sizeof(value));
/* handle */
for(i=0; i<10; i++)//3 change 10
{
/* start sw conversion */
AdcRegs.ADCTRL2.bit.RST_SEQ1 = 1; // Reset SEQ1
AdcRegs.ADCTRL2.bit.SOC_SEQ1 = 1; // sofware start ADC
/* wait conversion done */
delay_tmp = 1000;
while(delay_tmp--);
while(AdcRegs.ADCST.bit.INT_SEQ1 == 0);
/* value save */
value[0] += ((AdcRegs.ADCRESULT0) >> 4);
value[1] += ((AdcRegs.ADCRESULT1) >> 4);
value[2] += ((AdcRegs.ADCRESULT2) >> 4);
value[3] += ((AdcRegs.ADCRESULT3) >> 4);
value[4] += ((AdcRegs.ADCRESULT4) >> 4);
value[5] += ((AdcRegs.ADCRESULT5) >> 4);
value[6] += ((AdcRegs.ADCRESULT6) >> 4);
value[7] += ((AdcRegs.ADCRESULT7) >> 4);
value[8] += ((AdcRegs.ADCRESULT8) >> 4);
value[9] += ((AdcRegs.ADCRESULT9) >> 4);
value[10] += ((AdcRegs.ADCRESULT10) >> 4);
value[11] += ((AdcRegs.ADCRESULT11) >> 4);
value[12] += ((AdcRegs.ADCRESULT12) >> 4);
value[13] += ((AdcRegs.ADCRESULT13) >> 4);
value[14] += ((AdcRegs.ADCRESULT14) >> 4);
value[15] += ((AdcRegs.ADCRESULT15) >> 4);
}
tmp = (float)(value[chan-1]) / 10;
tmp = (3000 * tmp / 4095) ;
if(tmp >= 1499)
tmp += 1;
else;
paramData[3] = Type_Extrh_U8_Of_U16_TE(tmp);
paramData[4] = Type_Extrl_U8_Of_U16_TE(tmp);
}
把ADC模块的误差缩小到30MV 以内
