exp-dct-ad.c

基于Tms320C5402的 DCT 算法的源代码,该代码已经调试通过,运行结果良好

/***************************************************
The programme of the DCT.
Using INT2 to get the input signal.
Array x is the input signal from A/D, the length is 128, 32-bit floating point.
Array y is the compress data, the length is 128, 32-bit floating point.
Array z is the reconstruction signal, the length is 128, 32-bit floating point. 
****************************************************/
#pragma CODE_SECTION(vect,"vect")
#include <stdio.h>
#include "math.h"

#define IMR   *(pmem+0x0000)  
#define IFR   *(pmem+0x0001)  
#define PMST  *(pmem+0x001D)  
#define SWCR  *(pmem+0x002B)  
#define SWWSR *(pmem+0x0028) 
#define AL    *(pmem+0x0008) 
#define CLKMD  0x0058 /* clock mode reg*/

#define pi 3.1415927
#define Len 128


double x[Len],y[Len],z[Len];

void dct1c2 (double x[Len], double y[Len]);
void idct1c2 (double y[Len], double z[Len]);

unsigned int  *pmem=0;
ioport	unsigned char	port8001;
int in_x[Len];
int m = 0;
int intnum = 0;
double xmean=0;
int i=0;
int flag = 0;

void cpu_init()
{
   *(unsigned int*)CLKMD=0x0;         //switch to DIV mode clkout= 1/2 clkin
     while(((*(unsigned int*)CLKMD)&01)!=0);
   *(unsigned int*)CLKMD=0x27ff;      //switch to PLL 
	
	PMST=0x3FA0;
	SWWSR=0x7fff;
	SWCR=0x0000;
	IMR=0;
	IFR=IFR;
} 

interrupt void int2()   
{
	in_x[m] = port8001;
	in_x[m] &= 0x00FF;
	m++;
	intnum = m;
	
	if (intnum == Len)
	{
		intnum = 0;
		
		xmean = 0.0;
		
		for (i=0; i<Len; i++)
		{
			xmean = in_x[i] + xmean;
		}		
		
		xmean = 1.0*xmean/Len;
		
		for (i=0; i<Len; i++)
		{
			x[i] = (double)(in_x[i] - xmean);
		}
		
		dct1c2 (x,y);
						
		idct1c2 (y,z);
		
		m=0;
		flag = 1;
		
	}
}

  void dct1c2 (double x[Len], double y[Len])
  {
  		double s,t;
  		int i,j;
  		s=0.0;
   	for (i=0; i<Len; i++)
   	  {
   		s=s+x[i];
   	  }
   	
   	for (i=1; i<Len; i++)
      {
   		t=0.0;
   		for (j=0; j<Len; j++)
   		  {
   			t=t+x[j]*cos((2.0*j+1)*i*pi/(2.0*Len));
   		  }
   		y[i]=sqrt(2.0/Len)*t;
   	   }
   	y[0]=s/(sqrt(Len/1.0));
  }
  
  void idct1c2(double y[Len], double z[Len])
  {
  		double t;
  		int i,j;
  		for (i=0; i<Len; i++)
   	 	  {
		    t=0.0;
		    for (j=0; j<Len; j++)
		     {
		  	   t=t+y[j]*cos((2.0*i+1)*j*pi/(2.0*Len));
		     }
      		z[i]=y[0]/(sqrt(Len/1.0))+sqrt(2.0/Len)*t;
      	  }
  		
  }
 
void set_int()    
{
	asm(" ssbx intm");
	IMR=IMR|0x0004;  
	asm(" rsbx intm");  
}

void main(void)
{
	cpu_init();
	set_int();

	for(;;)
	{
		if (flag == 1)
		{
		   flag = 0;    /* set breakpoint here */

		}
	}
}

void vect()
{
   asm(" .ref _c_int00");  /*pseudoinstruction*/
   asm(" .ref _int2");

   asm(" b _c_int00");     /* reset */  
   asm(" nop");
   asm(" nop");
   asm(" rete");        
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" rete");
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" rete");
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" rete");
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" rete");
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" rete");
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" rete");
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" rete");
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" rete");
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" rete");
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" rete");
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" rete");
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" rete");
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" rete");
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" rete");
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" rete");      /* int0 */
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" rete");      /* int1 */
   asm(" nop");		   
   asm(" nop");
   asm(" nop");
   asm(" b _int2");   /* int2 */
   asm(" nop");
   asm(" nop");
   asm(" rete");      /* tint0 */
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" rete");      /* brint0 */
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" rete");      /* bxint0 */
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" rete");      /* dmac0 */
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" rete");      /* tint1 */
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" rete");      /* int3 */
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" rete");      /* hpint */
   asm(" nop");
   asm(" nop");
   asm(" rete");      /* brint1 */
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" rete");      /* bxint1 */
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" rete");      /* dmac4 */
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" rete");      /* dmac5 */
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" nop");
   asm(" nop");
}