DMA freezing ?

Hi guys,

I'm trying to make a simple design on my Intel Dev Kit MAX10 with the NIOS 2, DDR3 sdram controller and the DMA.

I write directly a pattern into my memory (1Gb in 64Mb*16) via NIOS 2 and DDR3 sdram controller, then I read back if it's well written (which is the case). And finally try to move one halfword (16bits) to another location an read again but I can't read...

I think everything is well setup in my Platform designer but then when I use the DMA to transfert data (I use registers, not HAL-drivers), I can't read back the memory...

Here is my config for the DMA :

while(IORD_ALTERA_AVALON_DMA_STATUS(DMA_BASE) == 0x02); //If DMA transaction is in progress then wait
 
IOWR_ALTERA_AVALON_DMA_CONTROL(DMA_BASE, 0x0);
IOWR_ALTERA_AVALON_DMA_STATUS(DMA_BASE, 0x0);
 
IOWR_ALTERA_AVALON_DMA_RADDRESS(DMA_BASE,0x0); //specifies the first location to be read in a DMA transaction
 
IOWR_ALTERA_AVALON_DMA_WADDRESS(DMA_BASE,0x2); //specifies the first location to be written in a DMA transaction
 
IOWR_ALTERA_AVALON_DMA_LENGTH(DMA_BASE,2); //specifies length (in Bytes) of transfert
 
IOWR_ALTERA_AVALON_DMA_CONTROL(DMA_BASE, 0x038A); //WCON, RCON, LEEN, GO, HW to 1
 
while(IORD_ALTERA_AVALON_DMA_STATUS(DMA_BASE) == 0x02);
 
IOWR_ALTERA_AVALON_DMA_STATUS(DMA_BASE, 0x0);
IOWR_ALTERA_AVALON_DMA_CONTROL(DMA_BASE, 0x0);

Thanks for your help !

PS : if you have any example of how to use the DMA (with registers, I've also tried with HAL-drivers but I wasn't able to make it work ^^') It will be really appreciated... I looked into UG embedded IP and NIOS 2 software developer's handbook but there's no example with registers...