Fft In Sopc

here is my code :

# include <stdio.h># include <unistd.h># include <stdlib.h># include <string.h># include <ctype.h>

# include "includes.h"# include "priv/alt_file.h"# include "sys/alt_cache.h"# include "sys/alt_alarm.h"# include "system.h"# include "io.h"# include "alt_types.h"

/*SGDMA Library*/# include <altera_avalon_sgdma.h># include <altera_avalon_sgdma_descriptor.h># include <altera_avalon_sgdma_regs.h>

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

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

alt_sgdma_dev * transmit_DMA;

alt_sgdma_dev * receive_DMA;

alt_u32 *tx_ptr;

alt_u32 *rx_ptr;

alt_sgdma_descriptor *desc = (alt_sgdma_descriptor*)INPUT_RAM_BASE ;

alt_sgdma_descriptor *desc1 = (alt_sgdma_descriptor*)OUTPUT_RAM_BASE ;

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

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

void init_FFT_sgdma()

{

/* Open a SG-DMA for MM-->ST and ST-->MM (two SG-DMAs are present) */

transmit_DMA = alt_avalon_sgdma_open("/dev/sgdma_mm_to_st_fft");

receive_DMA = alt_avalon_sgdma_open("/dev/sgdma_st_to_mm_fft");

// Making sure the SG-DMAs were opened correctly

if(transmit_DMA == NULL || receive_DMA == NULL)

printf("Could not open the SG-DMA of FFT\n");

add pointer to the input and output memory.

//tx_ptr pointer on memory where i will write input data

tx_ptr = (alt_u32 *) (INPUT_RAM_BASE+ ALTERA_AVALON_SGDMA_DESCRIPTOR_SIZE);

//rx_ptr pointer on memory where i can read output data

rx_ptr = (alt_u32 *) (OUTPUT_RAM_BASE+ ALTERA_AVALON_SGDMA_DESCRIPTOR_SIZE);

}

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

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

void Hardware_fourier_trans (N)

{

int i;

alt_8 *s0= (alt_8*)tx_ptr;

for(i = 0; i < N; i++)

{

tx_ptr = (alt_u32) (sig); //sig[1024] is array of input Signal

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

///////* maybe you will face problem whith arrange bytes whish transmit by SGDMA so you should rearrange bytes when you read from memory */

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

}

// Construct descriptors in the same input and output memory.

// here i use just one descriptorfor, if you want more than one replace "NULL" with name of next descriptor.

alt_avalon_sgdma_construct_mem_to_stream_desc(desc,NULL,tx_ptr, (alt_u16)4096,0,1,1,0);

alt_avalon_sgdma_construct_stream_to_mem_desc(desc1,NULL,rx_ptr,0,0);

//start transfer data

alt_avalon_sgdma_do_async_transfer(transmit_DMA, desc);

//wait to finish

while (IORD(SGDMA_MM_TO_ST_FFT_BASE,0)!=12) {};

//start receive data

alt_avalon_sgdma_do_async_transfer(receive_DMA, desc1);

while (IORD(SGDMA_ST_TO_MM_FFT_BASE,0)!=14) {};

//wait to finish

short *s1= (alt_8*)rx_ptr;

//calculate amplitude

for (i=0;i<1024;i++) {sig[i]=-1*sqrt(pow(s1[2*i],2)+pow(s1[2*i+1],2));}

}

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

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

int main(void)

{

init_FFT_sgdma();

return 0;

}

Good Luck