DMA ----send data from uart to SDRAM

Altera_Forum · ‎10-26-2010

I Have a program about DMA , isend data from RS232 to SDRAM, SDRAM can receive data ,bur when i check this data whther rightly, i find in't not the data that send from uart . the problem is i can't receive right data from uart. this problem have trouble me about 3 weeks .please give me a sugesttion and verify this programs. deeply thanks.

( Another program work rightly to send data from SDRAM to RS232 ,so SDRAM and RS232 work rightly)

PLEASE HELP ME,THANK YOU

the program is:

//字符串写到SDRAM,再从SDRAM读到RS232# include <stdio.h># include <stdlib.h># include "sys/alt_dma.h"# include "altera_avalon_uart_regs.h"# include "system.h"# include "alt_types.h"# include <string.h>

static volatile int tx_done = 0;

volatile static char str[] = {"this is sdram data，written by memcpy function\n"} ;//待写到SDRAM的数据# define TRANSFER_LENGTH 1024

//回调函数

static void done (void* handle)

{

tx_done++;

}

int main()

{

alt_u8 i;

FILE *fp_LCD=0;

FILE *fp_RS232=0;

fp_LCD = fopen("/dev/lcd","w");

fp_RS232 = fopen("/dev/rs232","w");

int rc;

alt_dma_txchan txchan;

void* source = (void*)(SDRAM_BASE);/* 源地址 */

void* dest = (void*)IOADDR_ALTERA_AVALON_UART_TXDATA(RS232_BASE);

//memset(SDRAM_BASE,'aaaaaaaaaaaaaaaa',TRANSFER_LENGTH);

memcpy(SDRAM_BASE,str,strlen(str)); //将STR地址中的字符串写到SDRAM

/* 打开发送通道 */

if ((txchan = alt_dma_txchan_open("/dev/dma")) == 0)

{ printf ("successful to open transmit channel\n");

exit (1);

}

/* 设置目标地址固定 */

if ((rc = alt_dma_txchan_ioctl(txchan, ALT_DMA_TX_ONLY_ON, dest)) < 0)

{ printf ("Failed to set ioctl, reason = %i\n", rc);

exit (1);

}

//设置每次发送一个字节，即8位，因为UART每次只发送8位

if((rc = alt_dma_txchan_ioctl(txchan,ALT_DMA_SET_MODE_8 ,NULL))<0)

{ printf("Failed to set mode 8\n");

exit(1);

}

/* 开始发送 */

if ((rc = alt_dma_txchan_send(txchan, source, strlen(str), done, NULL)) < 0)

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

exit (1);

}

/* 等待发送结束 */

while (!tx_done);

printf ("Transfer to jtag!\n");

fprintf(fp_LCD,"Transfer to lcd! \n");

fprintf(fp_RS232,"Transfer to rs232 ! \n");

for(i=0;i<=strlen(str);i++)

{

printf ("%s\n",(SDRAM_BASE+i));

fprintf(fp_LCD,(SDRAM_BASE+i));

//fprintf(fp_RS232,SDRAM_BASE);

}

return 0;

}

Altera_Forum · ‎10-26-2010

SORRY, the software visions :

quartus 10.0+NIOS 10.0

Altera_Forum · ‎03-12-2013

I need sdram to uart ,trying for 2 weeks but could not make it work.

will you share for me.I will be thankful to u.

Altera_Forum · ‎03-12-2013

it seems you need rx channel instead of tx channel.see embedded guide.