Help: SRAM DE2 Board

Besides, if possible, I need help with DMA too. I have lost idea of how to debug anymore. My DMA Controller setting in SOPC is Width of the DMA Register Length is set to 32bit and the rest is left at default. However, my system stucks (infinite loop) at

while (!txrx_done);

printf ("Transfer successful!\n");

I dont know why. i just follow the code exactly without editing anything.. but the creator can run it but i cant. i dont know what's the prob, i tried msg in the thread but no one replies.

my code (taken from one of the threads in the forum)

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# include <stdio.h># include <stdlib.h># include <stddef.h># include <string.h>

# include <system.h># include <io.h>

# include <alt_types.h># include "sys/alt_dma.h"# include "sys/alt_cache.h"# include "sys/alt_alarm.h"# include "alt_types.h"

static volatile int txrx_done = 0;

//callback function when DMA transfer done

static void txrxDone(void * handle, void * data)

{

txrx_done = 1;

}

void initMEM(int base_addr,int len)

{

for (int i=0;i<len;i++)

{

IOWR_8DIRECT(base_addr,i,i);

}

}

int main()

{

printf("testing ssram & sdram : dma operation\n");

alt_16 buffer[10];

//memset((void *)SSRAM_0_BASE,0x7a,0x10);//this write base on byte

initMEM(SDRAM_1_BASE,0x10);

memset((void *)(SDRAM_1_BASE+0x10),0x33,0x10);

printf("content of sdram_1:before DMA operation\n");

for (int i=0;i<0x10;i++)

{

printf("%d: %x\n",i,IORD_8DIRECT(SDRAM_1_BASE,i));

}

printf("content of sdram_1(offset 0x10):before DMA operation\n");

for (int i=0;i<0x10;i++)

{

printf("%d: %x\n",i,IORD_8DIRECT(SDRAM_1_BASE+0x10,i));

}

int rc; //request

alt_dma_txchan txchan;

alt_dma_rxchan rxchan;

void* tx_data = (void*)SDRAM_1_BASE; /* pointer to data to send */

void* rx_buffer = (void*)(SDRAM_1_BASE+0x10); /* pointer to rx buffer */

/* Create the transmit channel */

if ((txchan = alt_dma_txchan_open("/dev/dma_0")) == NULL)

{

printf ("Failed to open transmit channel\n");

exit (1);

}

/* Create the receive channel */

if ((rxchan = alt_dma_rxchan_open("/dev/dma_0")) == NULL)

{

printf ("Failed to open receive channel\n");

exit (1);

}

/* Post the transmit request */

if ((rc = alt_dma_txchan_send (txchan,

tx_data,

0x10,

NULL,

NULL)) < 0)

{

printf ("Failed to post transmit request, reason = %i\n", rc);

//exit (1);

}

/* Post the receive request */

if ((rc = alt_dma_rxchan_prepare (rxchan,

rx_buffer,

0x10,

txrxDone,

NULL)) < 0)

{

printf ("Failed to post read request, reason = %i\n", rc);

//exit (1);

}

/* wait for transfer to complete */

while (!txrx_done);

printf ("Transfer successful!\n");

printf("content of sdram_1:after DMA operation\n");

for (int i=0;i<0x10;i++)

{

printf("%d: %x\n",i,IORD_8DIRECT(SDRAM_1_BASE,i));

}

printf("content of sdram_1(offset 0x10):after DMA operation\n");

for (int i=0;i<0x10;i++)

{

printf("%d: %x\n",i,IORD_8DIRECT(SDRAM_1_BASE+0x10,i));

}

return 0;

}

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