adc.c

s3c44b0+sl811读写u盘程序

/****************************************************************
 *		   S3C44B0X  ADC TEST								*  
 ****************************************************************
 
  ADC TEST
 
 ***************************************************************/
 
#include <string.h>
#include "..\target\44b.h"
#include "..\target\44blib.h"
#include "..\inc\adc.h"

void Test_Adc(void)
{
    int a0=0,a1=0,a2=0,a3=0,a4=0,a5=0,a6=0,a7=0;
    int adcpsr;

    Uart_Printf("现在开始A/D转换自检测试!!!!\n");	      
    Uart_Printf("按任意键退出!!!!\n");	 

    rCLKCON=0x7ff8;	
    rADCCON=0x1|(0<<2);		//Enable ADC
    Delay(100);	//delay for 10ms for ADC reference voltage stabilization.

    //Uart_Printf("Input ADCPSR value:");
    //adcpsr=Uart_GetIntNum();
    adcpsr=255;
    rADCPSR=adcpsr;
    Uart_Printf("ADC转换频率=%d(Hz)\n",(int)(MCLK/(2.*(adcpsr+1.))/16.) );
    
    while(Uart_GetKey()==0)
    {
    Delay(5000);	//delay for 500ms for ADC 
	a0=ReadAdc(0);
	a1=ReadAdc(1);
	a2=ReadAdc(2);
	a3=ReadAdc(3);
	a4=ReadAdc(4);
	a5=ReadAdc(5);
	a6=ReadAdc(6);
	a7=ReadAdc(7);
	Uart_Printf("\n通道0:%04d  通道1:%04d  通道2:%04d  通道3:%04d \n",a0,a1,a2,a3);
	Uart_Printf("通道4:%04d  通道5:%04d  通道6:%04d  通道7:%04d \n",a4,a5,a6,a7);
    }
}

int ReadAdc(int ch)
{
    int i;
    static int prevCh=-1;

    if(prevCh!=ch)
    {
    	rADCCON=0x0|(ch<<2);	//setup channel.
    	for(i=0;i<150;i++);	//min. 15us
    }
    rADCCON=0x1|(ch<<2);	//Start A/D conversion
    while(rADCCON &0x1);	//To avoid The first FLAG error case.
				//(The START bit is cleared in one ADC clock.)
    while(!(rADCCON & 0x40));
    for(i=0;i<rADCPSR;i++); 	//To avoid The second FLAG error case
    prevCh=ch;
    return rADCDAT;
}