Honored ContributorHello, may I know where can I get NiosII DMA Tutorial? Currently, I am doing a project to implement DMA on FPGA board. So I would to refer to some tutorials that can help me. Thanks.
Honored ContributorHmm.. I see.
Ok Cris, I'll try with a simple FIFO first. If it is succeed, later I'll integrate my FIFO with the Nios-II system. Thanks a lot Cris!Honored ContributorHi Cris
Long time no see. Thank you for helping me last time. Now I can do data transfer from FIFO to DDR3 via DMA correctly. However, this time I would like to ask your suggestion again. Currently I'm using three DMAs in my SOPC system to handle three different data transfers from three different FIFOs to a DDR3 memory. I have verified each FIFO and DMA data transfer and all of them work well. The problem occurs when I put all FIFOs and DMAs in one SOPC system design. I ran the DMA data transfer in sequence (not parallel). Somehow my Nios software hung / stopped. From the Nios software debugging, it was noticed that the Nios software might stop in different location, but mostly it stopped when it tried to open the DMA ('alt_dma_rxchan_open' function) or when it checked the DMA data transfer volatile indicator variable. Do you have any idea what caused my software hung? Or do you have any suggestion how to figure out the reason behind this problem? Thanks ... looking forward any replies from you guys!Honored ContributorHi,
I saw you opened a thread on this topic yesterday, but I had no certain solution, so I didn't answer. The only thing I can think about it is timing problems; is your design fully constrained and does it meet timing? Have you also checked interrupt or arbitration priorities; is it possible you have a highest priority interrupt which is blocking everything? I'd run in debug mode and step into alt_dma_rxchan_open to see the exact point where code hangs.Honored ContributorHi Cris,
Finally I know what's wrong with my program. :) Actually it was caused by a misplacement 'waitrequest' signal in the avalon slave MM. So this misplaced 'waitrequest' signal caused the 'write' signal from CPU kept high and blocked other process. Now my system and its program can work correctly :) Btw Cris, I have some questions about RS-485 (in a new thread), I'm really appreciate if you want to help me :) Thanks :)Honored ContributorHello i am trying to do the same thing that you did, but i am kinda new to software development for NIOS. And i would like to get a "start point" i've read a lot of altera documentation but i can't find a simple "read from a memory" and "write in another memory" design/tutorial with the hardware and the software.
I made a system consisting of a SDRAM, SGDMA and a NIOS. I want to write something to the DMA and that the dma writes the same data to the SDRAM. DO you have any piece of sw code that do something like that? Thanks a lot.Honored ContributorHi aprado,
I have this piece of code for a simple dma core. I think you need to make a few changes in order to use with your sgdma core.# include "sys/alt_dma.h"# include "altera_avalon_dma.h"
# define DMA_LENGTH 512
volatile int dma_complete;
short rx_buffer; // pointer to rx buffer
short tx_buffer; // pointer to tx buffer
void dma_done (void* handle, void* data)
{
int rc;
// turn the LED off (for DEBUG)
rc = IORD_ALTERA_AVALON_PIO_DATA(LED_PIO_BASE);
IOWR_ALTERA_AVALON_PIO_DATA(LED_PIO_BASE, rc & ~0x10);
dma_complete = 1;
}
int test_dma(void)
{
int rc;
alt_dma_txchan txchan;
alt_dma_rxchan rxchan;
void* tx_data = (void*) tx_buffer; // pointer to data to send
dma_complete = 0;
// Create the transmit channel
if ((txchan = alt_dma_txchan_open("/dev/ts_dma")) == NULL) {
printf ("Failed to open transmit channel\n");
return -1;
}
// Create the receive channel
if ((rxchan = alt_dma_rxchan_open("/dev/ts_dma")) == NULL) {
printf ("Failed to open receive channel\n");
return -2;
}
if(alt_dma_txchan_ioctl(txchan, ALT_DMA_SET_MODE_16, NULL)<0) {
return -3;
}
if(alt_dma_rxchan_ioctl(rxchan,ALT_DMA_SET_MODE_16,NULL)<0) {
return -4;
}
if(alt_dma_txchan_ioctl(txchan,ALT_DMA_TX_ONLY_OFF,NULL)<0) {
return -5;
}
if(alt_dma_rxchan_ioctl(rxchan,ALT_DMA_RX_ONLY_OFF,NULL)<0) {
return -6;
}
printf ("Test DMA transfer...\n");
// turn a LED on (for DEBUG)
rc = IORD_ALTERA_AVALON_PIO_DATA(LED_PIO_BASE);
IOWR_ALTERA_AVALON_PIO_DATA(LED_PIO_BASE, rc | 0x10);
// Post the transmit request
if ((rc = alt_dma_txchan_send (txchan,tx_data,DMA_LENGTH-16,NULL,NULL)) < 0) {
printf ("Failed to post transmit request, reason = %i\n", rc);
return -7;
}
// Post the receive request
if ((rc = alt_dma_rxchan_prepare (rxchan,rx_buffer,DMA_LENGTH-16, dma_done,NULL)) < 0) {
printf ("Failed to post read request, reason = %i\n", rc);
return -8;
}
// wait for transfer to complete
while (!dma_complete)
TK_SLEEP(10);
printf ("Transfer successful!\n");
return 0;
}
@ Aprado
Hi, you can also learn about it from here http://www.alteraforum.com/forum/showthread.php?t=16850&highlight=dma+about , they discussed about DMA-memory data transfer and shared some code @ Cris Hi Cris, sorry for asking you again using this thread. Currently I'm discussing a problem about changing Nios's IP address in other thread http://www.alteraforum.com/forum/showthread.php?p=105881#post105881 . If you don't mind, please kindly to check it, maybe you have some advices for my problem :( Thank you!Honored ContributorThanks a lot for this posts, Cris i can tranfer from my onchip memory to my sdram memory without any problems. But now i want to do something differnt. Really simmilar to what fightingdreamer did.
I have a fifo outside my sopc system that is connected to a 8bits PIO in my sopc system. I want to read this 8 bits from my PIO and write to a DDR memory. How should the code look like? (While i ask i am trying to modify your code) Thanks a lot. Fightingdreaming, do you have any tips? I saw you did exactly what i am trying to do.Honored ContributorHonored ContributorCool, how can i set it in the software? I see is the 8th bit that i must set to 1. Where can i find examples of that? Thanks
