我在NIOS2中加入了DMA外设

现透过DMA来传输两个数组中的数据,但是为何传送后的数据有问题?

例如传输前是1.2.3.4.5.6.7.8.9

传送后就变为1.2.4.3.6.5.11.9.8

我的程序是

#include "system.h"

#include "altera_avalon_pio_regs.h"
#include "altera_avalon_uart_regs.h"
#include "altera_avalon_timer_regs.h"
#include "altera_avalon_dma_regs.h"

#include "alt_types.h"
#include "sys/alt_irq.h"

 
alt_u8 *p_sbuff;
 
volatile alt_u8 chr[] = {1,2,3} ;
volatile alt_u8 chr2[20] ;
 
  alt_u8 chars = 'y';

void DMA0_init();

/**********************************************************************
 *
 * Function:    int main()
 *
 * Description: The main function
 *             
 *
 * Notes:      
 *
 * Returns:     None defined.
 *
 **********************************************************************/
int main (void)
{

  DMA0_init();//start dma

   while (1)
  {
    }

  return 0;
}

/**********************************************************************
 *
 * Function:    DMA0_Init()
 *
 * Description:  Initialize The DMA0
 *             
 *
 * Notes:      
 *
 * Returns:     None defined.
 *
 **********************************************************************/

void DMA0_init()
{
  alt_u16 control_value;
 
  IOWR_ALTERA_AVALON_DMA_STATUS(DMA_0_BASE, 0x00);  //Clear the status register
  IOWR_ALTERA_AVALON_DMA_RADDRESS(DMA_0_BASE, chr);  //Write the read dress  , for
  IOWR_ALTERA_AVALON_DMA_WADDRESS(DMA_0_BASE, chr2);  //Write the write dress , for UART0
  IOWR_ALTERA_AVALON_DMA_LENGTH(DMA_0_BASE, 0x10);  //Send eight bytes
 
  control_value = ALTERA_AVALON_DMA_CONTROL_HW_MSK+ALTERA_AVALON_DMA_CONTROL_GO_MSK + ALTERA_AVALON_DMA_CONTROL_LEEN_MSK ;    
  IOWR_ALTERA_AVALON_DMA_CONTROL(DMA_0_BASE, control_value);    

}