fdmac2isr.c

以DMA方式实现的fft程序

#include <codec.h>
#include <firlab.h>
#include <dsplib.h>
#include <math.h>

extern  void delay(s16 period);
extern	unsigned int channel;      /*IN: DMA channel number              */
extern	unsigned int dmsefc;       /*IN: Value to set sync & fr reg      */
extern	unsigned int dmmcr;        /*IN: Value to set mode control reg   */
extern	unsigned int dmctr;	   	  /*IN: Value to set element count reg  */
extern	unsigned int src_page;     /*IN: Value to set source page reg    */
extern	unsigned int src_addr;     /*IN: Value to set source addr reg    */
extern	unsigned int dst_page;     /*IN: Value to set dest page reg      */
extern	unsigned int dst_addr;     /*IN: Value to set dest addr reg      */

extern DATA inp_buffer[0x200];
extern DATA out_buffer[0x200];
extern int frame; 
extern int flag;
extern int currbuff;
DATA  y[256];
u16  f[128];

void	init_dma3(void)
{
	    	while(DMPREC&0x0008) {};	//DMA3的传送是否结束
	    
	    	/* Initialize DMA channel 3 */

			dmsefc = ((DSYNC_REVT1 <<12));
    		dmmcr = 0x4141;			//AUTOINIT=0,DINM=1,IMOD=0,CTMOD=0,SIND=0x001;DMS=0x01,DIND=0x000,DMD=0x01
    		dmctr = 0xFF;			//256 element/frame
    	    src_addr = (unsigned int) &out_buffer+((unsigned int)frame*0x100);
    		dst_addr = DXR1_ADDR(HANDSET_CODEC);
    		dma_init(DMA_CH3, dmsefc, dmmcr, dmctr, SPACE_DATA, src_addr, SPACE_DATA, dst_addr);

		/* Set number of frames for channel 3 */
    
    		DMA_FRAMECOUNT(DMA_CH3, 0);		//2 frame/block
    		
    		/* Enable channel 3 */

    		DMA_ENABLE(DMA_CH3);
}

interrupt void DMAC2ISR(void)
{
	DATA *p_inp,*p_out; 
    int i,m,k;
	double p,q,tp;
		
	p_inp=inp_buffer+frame*0x100;
	p_out=out_buffer+frame*0x100;

	for (i=0;i<256;i++)
		*(p_out+i)=*(p_inp+i);

    init_dma3();
	frame^=1;

	cbrev(p_inp,y,128);
	rfft(y,256,1);
	f[0]=abs(y[0]);

	m=1;
	for(k=2;k<256;k=k+2)
	{
		p=y[k];
        q=y[k+1];
        tp=p*p+q*q;
        tp=sqrt(tp); 
        f[m]=tp;
        m++;
	}

}