fir16d.c

TMS320X281x滤波库源码及测试程序

/* ==============================================================================

System Name:    Generic FIR Filter Demo, This system uses FIRFILT_GEN module

File Name:      FIRGD.C

Description:    Primary System file for demonstrating the FIR Filter

Originator:     Digital control systems Group - Texas Instruments

Target dependency:  C28x
Description:
============

This software demonstrates the FIR Filter Usage

   The frame work, for demonstrating the FILTER is given below
   
   
   CH0  |--------------|           |------------|               |-----------|
   ---->|              |           |            |               |           |
   CH0  |              |           |            |               |           |         
   ---->|              |     input |            | Output        |  EVMDAC   |
   CH0  |   ADC04U_DRV |-----|---->|    FIR     |-------------->|  PWMDAC   |
   ---->|              |     |     |   FILTER   |               |  DATALOG  |
   CH0  |              |     |     |            |          |--->|           |
   --|->|              |     |     |            |          |    |           |
        |--------------|     |     |------------|          |    |-----------|
                             |                             |
                             |-----------------------------|
 
*/

#include <sgen.h>
#include <dlog4ch.h>
#include <fir.h>

/* Create an instance of Signal generator module    */
SGENTI_1 sgen = SGENTI_1_DEFAULTS;

/* Create an instance of DATALOG Module             */
DLOG_4CH dlog=DLOG_4CH_DEFAULTS;      
    
/* Filter Symbolic Constants                        */
#define FIR_ORDER   50                                        
                                        
/* Create an Instance of FIRFILT_GEN module and place the object in "firfilt" section       */ 
#pragma DATA_SECTION(fir, "firfilt");
FIR16  fir= FIR16_DEFAULTS;
                                            
/* Define the Delay buffer for the 50th order filterfilter and place it in "firldb" section */  
#pragma DATA_SECTION(dbuffer,"firldb");
long dbuffer[(FIR_ORDER+2)/2];                                        
         
/* Define Constant Co-efficient Array  and place the
.constant section in ROM memory				*/ 

long const coeff[(FIR_ORDER+2)/2]= FIR16_LPF50;
         
         
/* Finter Input and Output Variables                */   
int xn,yn;
     
void main()
{    

/* Signal Generator module initialisation           */ 
       sgen.offset=0;
       sgen.gain=0x7fff;        /* gain=1 in Q15                              */
       sgen.freq=9830;          /* freq = (Required Freq/Max Freq)*2^15       */
                                /*      = (3000/10000)*2^15 = 5369             */         
       sgen.step_max=0x7FFF;    /* Max Freq= (step_max * sampling freq)/65536 */
                                /* Max Freq = (32767*20k)/65536 = 10,000      */

/* DATALOG module initialisation                    */        
       dlog.iptr1=&xn;  
       dlog.iptr2=&yn;
       dlog.trig_value=0x800;
       dlog.size=0x400;         
       dlog.init(&dlog);

/* FIR Generic Filter Initialisation    */ 
       fir.order=FIR_ORDER; 
       fir.dbuffer_ptr=dbuffer;
       fir.coeff_ptr=(long *)coeff; 
       fir.init(&fir);
              

/*---------------------------------------------------------------------------
    Nothing running in the background at present           
----------------------------------------------------------------------------*/

        while(1) 
        {
            sgen.calc(&sgen);
            xn=sgen.out;
            fir.input=xn;           
            fir.calc(&fir);
            yn=fir.output;
            dlog.update(&dlog);
        }       

} /* End: main() */