adc.dsp

非常实用的AD和pwm的ad公司21990dsp芯片的控制源代码

/****************************************************************************************
*										       											*
*  Library: Configuration of ADC block 	for simulataneous sampling					   	*
*																						*
* File: adc.dsp								       										*
*										       											*
* Description:  adc code file						       								*
* Purpose    : Library routines for ADC block operation									*
* 										       										    *
* Author     : JC								       									*
* Version    : 1.0								       									*
* Date       : Mar 2002                                                            		*
* Modification History:    none							       							*
*										       											*
* Embedded Control Systems							       								*
* Analog Devices Inc.								       								*
****************************************************************************************/

#include <main.h>;

/***************************************************************************************
* Calculate Configuration Register Contents from Parameters                            *
***************************************************************************************/
/*None*/
/***************************************************************************************
* Constants Defined in the Module                                                      *
***************************************************************************************/
#define ADC_SF						32768/ADC_Number_of_samples/4 // value of (1/ADC_NUmber_of_samples/4)	

/***************************************************************************************
* Routines Defined in this Module                                                      *
***************************************************************************************/

.global  ADC_Init_;
.global  ADC_Scale_;

/***************************************************************************************
* Global Variables Defined in this Module                                              *
***************************************************************************************/
.section/data seg_dmdata;
.VAR Offset_0to3 =0;
.VAR Offset_4to7 =0;

.global Offset_0to3;
.global Offset_4to7;


/***************************************************************************************
* Local Variables Defined in this Module                                               *
***************************************************************************************/

/* None*/ 

/***************************************************************************************
*                                                                                      	*
* Type: Routine                                                       		       		*
*                                                                                      	*
* Call: call ADC_Init_;                                                                	*
*                                                                                      	*
* Initialises the ADC block and calculate the offsets and set into simultaneous sampling*
*                                                                                      	*
* Inputs  :   	ADC_Number_of_samples                                                	*
*                                                                                      	*
* Ouputs  :		mr1:Offset_0to3
*				sr1:Offset_4to7
*                                                                                      	*
* Modified:	    ar, af, ax0, ay0, ay1, mr,  mx0, my0, sr, px, I4                                                 					*
*                                                                                      *
***************************************************************************************/
.section/pm seg_pmcode;

ADC_Init_:				// Initialise ADC block 

	iopg = IntCtrl_Page;
	ar = IO(IPR3);
	ay0 = 0x0fff;
	ar = ar and ay0;
	ay0= 0x2000;		/*assign ADC EOC ISR to USR2*/
	ar = ar or ay0;
	IO(IPR3) = ar;

	iopg = ADC_Page; 
	ar=0x0227;			//set up ADC as SW conv start and offset calibration mode
	IO(ADC_CTRL)=ar;
	

	sr=0;
	mr=0;
	my0=ADC_SF;			//load the scaling factor for averaging samples
	ay1=0x000F;			//use to check if all channels are converted bit 0-3 of ADCSTAT
 	
	CNTR=ADC_Number_of_samples;
	do offset_loop until CE;
	
	ar=0x0001;
	IO(ADC_SOFTCONVST)=ar; //start ADC by software conv start
wait_loop:	ar=IO(ADC_STAT);
			ar=ar and ay1;
			ar=ar-ay1;     //ay1=0x000F
			if NE jump wait_loop;// check if all chanenels are converted

	mx0=IO(ADC_DATA0);
	mr=mr+mx0*my0(ss);
	mx0=IO(ADC_DATA1);
	mr=mr+mx0*my0(ss);	
	mx0=IO(ADC_DATA2);
	mr=mr+mx0*my0(ss);
	mx0=IO(ADC_DATA3);
	mr=mr+mx0*my0(ss);//calculate Offset_0to3

	mx0=IO(ADC_DATA4);
	sr=sr+mx0*my0(ss);
	mx0=IO(ADC_DATA5);
	sr=sr+mx0*my0(ss);	
	mx0=IO(ADC_DATA6);
	sr=sr+mx0*my0(ss);
	mx0=IO(ADC_DATA7);
offset_loop:	sr=sr+mx0*my0(ss);//calculate Offset_4to7
	sat mr;
	sat sr;

	DM(Offset_0to3)=mr1;//store average of VIN0 to VIN3
	DM(Offset_4to7)=sr1;//store average of VIN4 to VIN7

	ar=0x0200;
	IO(ADC_CTRL)=ar;	//set ADC to simultaneous sampling and PWMSync conv start

rts;

/**************************************************************************************
*                                                                                     *
* Type: Routine                                                                       *
*                                                                                     *
* Call: ADC_Scale_;                                                                   *
*                                                                                     *
* Used to compensate for offset in the ADC			                      			  *
*                                                                                     *
* Inputs  :   	None                                                                  *
*                                                                                     *
* Ouputs  :		ar- ADC channel value after offset                                                                      *
*                                                                                     *
* Modified:	    ar, ay0                                                                    *
*                                                                                     *
**************************************************************************************/

ADC_Scale_:

	ena ar_sat;
	ar = ar - ay0;      		//The Offset voltage is taken in consideration 
	dis ar_sat;

rts;


////////////////////////////////////////////////////////////////