Altera_Forum
Honored Contributor
Honored Contributorhelp with simple memory testing example on niosII
hi all,
im just a beginner trying to run memory test example code provided in nios EDS. What ive wanted to do is simply running a test on SDRAM (with dma). Ive configure the SOPC with SDRAM & dma controller. The screenshot of my sopc is shown below: https://www.alteraforum.com/forum/attachment.php?attachmentid=2385 While running the c code example, the program pass all the test but stay still when it comes to "testing memory using dma". I ran it again in debug mode and put breakpoints in certain places. What i found out is that it never get out of while(!rx_done). It seems like the dma transfer is never completed and rx_done is always 0. Here is the code snippet of the memory test (consist only the function called for dma test)/******************************************************************
* Function: dma_done
*
* Purpose: Called when a DMA recieve transaction is complete.
* Increments rx_done to signal to the main program that
* the transaction is done.
*
******************************************************************/# ifdef DMA_NAME
static void dma_done (void* handle, void* data)
{
rx_done++;
}# endif /* DMA_NAME */
/******************************************************************
* Function: MemDMATest
*
* Purpose: Tests every bit in the memory device within the
* specified address range using DMA. The DMA controller provides
* a more rigourous test of the memory since it performs back-to-
* back memory accesses at full system speed.
*
******************************************************************/# ifdef DMA_NAME
static int MemDMATest(unsigned int memory_base, unsigned int nBytes)
{
int rc;
int ret_code = 0;
int pattern, offset;
alt_dma_txchan txchan;
alt_dma_rxchan rxchan;
void* data_written;
void* data_read;
/* Get a couple buffers for the test */
data_written = (void*)alt_uncached_malloc(0x1000);
data_read = (void*)alt_uncached_malloc(0x1000);
/* Fill write buffer with known values */
for (pattern = 1, offset = 0; offset < 0x1000; pattern++, offset+=4)
{
IOWR_32DIRECT((int)data_written, offset, pattern);
}
/* Create the transmit channel */
if ((txchan = alt_dma_txchan_open("/dev/dma")) == NULL)
{
printf ("Failed to open transmit channel\n");
exit (1);
}
/* Create the receive channel */
if ((rxchan = alt_dma_rxchan_open("/dev/dma")) == NULL)
{
printf ("Failed to open receive channel\n");
exit (1);
}
for(offset = memory_base; offset < (memory_base + nBytes); offset += 0x1000)
{
/* Use DMA to transfer from write buffer to memory under test */
/* Post the transmit request */
if ((rc = alt_dma_txchan_send (txchan, data_written, 0x1000, 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, (void*)offset, 0x1000, dma_done, NULL)) < 0)
{
printf ("Failed to post read request, reason = %i\n", rc);
exit (1);
}
/* Wait for transfer to complete */
while (!rx_done);
rx_done = 0;
/* Clear the read buffer before we fill it */
memset(data_read, 0, 0x1000);
/* Use DMA to read data back into read buffer from memory under test */
/* Post the transmit request */
if ((rc = alt_dma_txchan_send (txchan, (void*)offset, 0x1000, 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, data_read, 0x1000, dma_done, NULL)) < 0)
{
printf ("Failed to post read request, reason = %i\n", rc);
exit (1);
}
/* Wait for transfer to complete */
while (!rx_done);
rx_done = 0;
if (memcmp(data_written, data_read, 0x1000))
{
ret_code = offset;
break;
}
}
alt_uncached_free(data_written);
alt_uncached_free(data_read);
return ret_code;
}# endif /* DMA_NAME */ 
