用TMS320F28335和AD7656进行采样，官方给的例程如下：想请教一下这个AD7656_BASIC变量一直指代的是0x200000中的值，如果地址不发生改变的话，怎么读取其他数据，难道所有数据都存储在地址0x200000中了吗
//在定时器内进行采样,采样率1.5KHz
#include "DSP2833x_Device.h" // DSP2833x Headerfile Include File
#include "DSP2833x_Examples.h" // DSP2833x Examples Include File
#define AD7656_BASIC (*((volatile Uint16 *)0x200000))
//#define AD7656_rst (*((volatile Uint16 *)0x200008))
#define AD_BUSY GpioDataRegs.GPBDAT.bit.GPIO60
#define SET_ADRST GpioDataRegs.GPBSET.bit.GPIO61=1
#define CLEAR_ADRST GpioDataRegs.GPBCLEAR.bit.GPIO61=1
#define SET_ADCLK GpioDataRegs.GPASET.bit.GPIO25=1
#define CLR_ADCLK GpioDataRegs.GPACLEAR.bit.GPIO25=1
Uint16 ad[6];
void InitXintf(void);
//int test[256];
long sampleCount=0;
Uint16 testSample1[256],testSample2[256],testSample3[256],//6个数组存放AD数据
testSample4[256],testSample5[256],testSample6[256];
int i;
interrupt void ISRTimer0(void);
void ADInit(void)
{
EALLOW;
GpioCtrlRegs.GPAMUX2.bit.GPIO25=0;//对应ADCOV脚,CONVSTA、B、C
GpioCtrlRegs.GPADIR.bit.GPIO25=1;//设置为GPIO输出模式
GpioCtrlRegs.GPBMUX2.bit.GPIO61 = 0; // XWE0//对应ADRST脚
GpioCtrlRegs.GPBDIR.bit.GPIO61=1;//设置为GPIO输出模式
GpioCtrlRegs.GPBMUX2.bit.GPIO60=0; //ADBUSY//对应ADBUSY脚
GpioCtrlRegs.GPBDIR.bit.GPIO60=0;//INPUT//设置为GPIO输入模式
GpioCtrlRegs.GPBQSEL2.bit.GPIO60= 0;//设置与系统时钟同步触发
EDIS;
}
void main(void)
{
InitSysCtrl();
InitXintf();
InitXintf16Gpio();//AD7656中的DB0-DB15对应F28335中的XD0-XD15对应GPIO79-GPIO64//初始化外部SRAM的地址线，数据线，片选线
ADInit();
DINT;
InitPieCtrl();
IER = 0x0000;//禁止CPU中断
IFR = 0x0000;//清除CPU中断标志
InitPieVectTable();//基本初始化
EALLOW; // This is needed to write to EALLOW protected registers
PieVectTable.TINT0 = &ISRTimer0;//将中断地址赋给你要写的中断；设置定时器0的中断入口地址为中断向量表的INT0
EDIS; // This is needed to disable write to EALLOW protected registers
InitCpuTimers(); // For this example, only initialize the Cpu Timers
ConfigCpuTimer(&CpuTimer0, 100, 987); //在定时器内进行采样,采样率1.5KHz
IER |= M_INT1;//开启CPU第一组中断
PieCtrlRegs.PIECTRL.bit.ENPIE = 1;
PieCtrlRegs.PIEIER1.bit.INTx7 = 1; //使能第一组中断中的第7个小中断，即定时器0
EINT; //使能总中断
ERTM; //使能仿真调试中断
/*EALLOW;
GpioCtrlRegs.GPAMUX1.bit.GPIO0 = 0; // GPIO0 = GPIO0
GpioCtrlRegs.GPADIR.bit.GPIO0 = 1;
EDIS;
GpioDataRegs.GPADAT.bit.GPIO0 = 0;*/
SET_ADRST;
DELAY_US(100000);
CLEAR_ADRST;
StartCpuTimer0();//开启定时器功能
while(1);
}
interrupt void ISRTimer0(void)
{
CLR_ADCLK; //启动转换信号
DELAY_US(1); //给予适当的电平延时
SET_ADCLK;
DELAY_US(1);
//GpioDataRegs.GPADAT.bit.GPIO0 = ~GpioDataRegs.GPADAT.bit.GPIO0;
while(AD_BUSY) //等待转换结束
{
}
for(i=0;i<6;i++)
{
ad[i]=AD7656_BASIC; //读取6路AD通道数据
}
testSample1[sampleCount]=ad[0];//存放在数组里
testSample2[sampleCount]=ad[1];
testSample3[sampleCount]=ad[2];
testSample4[sampleCount]=ad[3];
testSample5[sampleCount]=ad[4];
testSample6[sampleCount]=ad[5];
sampleCount++;
if(sampleCount >= 255) sampleCount=0;
PieCtrlRegs.PIEACK.all = PIEACK_GROUP1;
CpuTimer0Regs.TCR.bit.TIF=1; // 定时到了指定时间，标志位置位，清除标志
CpuTimer0Regs.TCR.bit.TRB=1; // 重载Timer0的定时数据
}
