[chema15]

Hi, I wrote a function in C to W SDRAM memory :

void write_sdram()
{
int *buffer = (int *) 0x00800000; // SDRAM addr base

buffer[0]=0xaaaa;
buffer[1]=0xcccc;
}

When I read the SDRAM with altera DE1 control panel data is :
addr 0 = aaaa
addr 1 = 0000
addr 2 = cccc
addr 3 = 0000

Why ??? If the SDRAM data width is 16 bits , I'm waiting for
addr 0 = aaaa
addr 1 = cccc


Help me please !!!!!

[aukums]

Could it be because int is 32 bits data type variable? Try alt_u16 for buffer and I think this will work.

Originally Posted by chema15

Hi, I wrote a function in C to W SDRAM memory :

void write_sdram()
{
int *buffer = (int *) 0x00800000; // SDRAM addr base

buffer[0]=0xaaaa;
buffer[1]=0xcccc;
}

When I read the SDRAM with altera DE1 control panel data is :
addr 0 = aaaa
addr 1 = 0000
addr 2 = cccc
addr 3 = 0000

Why ??? If the SDRAM data width is 16 bits , I'm waiting for
addr 0 = aaaa
addr 1 = cccc


Help me please !!!!!

[chema15]

Ok , Thanks !!!!! it was the solution, but now I have another problem:

I want to write some data in SDRAM with a FOR cicle and connect the audio codec MIC (in) to audio codec spk(out), the audio code segment is ok, the problem is when I add the write sdram function because the program stops, I saw (before running program) that initially some data (probably code) is in sdram memory and I think maybe the write sdram function is changing the program code. Here the question is: Why program data in SDRAM if I configured in SOPC builder reset and exception vector in SRAM ??? What I can do to put the code program on SRAM and not SDRAM.

Here the code :

#include "sdram_to_audio.h"

long i;
alt_u16 cont=0;

void write_sdram()
{
alt_u16 *buffer = (alt_u16 *) 0x00800000; // base addr SDRAM

for (i=0; i<=127; i++){
buffer[i]=cont;
cont++;
}
}

int main()
{
volatile int * audio_ptr = (int *) 0x10003040; // audio port
long audiobuf[128];

/* used for audio record/playback */
int fifospace;//, leftdata, rightdata;
int buffer_index = 0;

write_sdram();

while (1)
{
fifospace = *(audio_ptr+1); // read the audio port fifospace register

if ((fifospace & 0x000000FF) > 96)
{
audiobuf[buffer_index] = *(audio_ptr + 3); // read right channel only
buffer_index++;
}

fifospace = *(audio_ptr+1); // read the audio port fifospace register

if (((fifospace & 0x00ff0000)>>16) > 96) {
buffer_index--;
//Write to both channels
*(audio_ptr + 2) = audiobuf[buffer_index];
*(audio_ptr + 3) = audiobuf[buffer_index];

}
}
}

[aukums]

Right click in your project and click "System library properties". Make sure that program memory, stack memory, etc are all set to SRAM and not SDRAM.

Kumaran

[chema15]

I'm sure all it's correct (SOPC builder, and monitor program are configure with SRAM) but running the program some code (maybe program code is on SDRAM) and when I execute the write sdram function it writes a zone with code causing the program stops.....

[chema15]

Thanks for the answer , my configuration is ok, now I can write exactly on SDRAM but the problem appears if the number of data to write on sdram is for example 1000, why ?? if the memory is 8 MB

[chema15]

I found the solution !!!!!!!!!!! my system has a timer and my C program doesn't have a handler for timer interrupt, If I don't use the timer I have to desactivate it on system properties.


Thanks for your help !!!!!!!!!!!!!!!!!!!!!!!