write & read SDRAM chip

hi all

I try to read and write the external 8M SDRAM chip.

At the Nios II IDE, my system library and "Linker Script" with program memory(.text), Read-only data memory(.rodata), Read/Write data memory (.rwdata), Heap memory, Stack memory all setting another RAM chip "sram_0".

My program is below:

# include <stdio.h># include <alt_types.h># include <io.h># include <system.h># include <string.h># include "system.h"

int main(void)

{

unsigned int value = 0;

unsigned int pattern = 0x10;

unsigned int i, memory_size;

memory_size = 0x800;

//SDRAM actual size is 0x7FFFFF

for(i = 0; i< memory_size; i=i+0x10)

{

IOWR_16DIRECT((SDRAM_0_BASE), i, pattern);

value = IORD_16DIRECT((SDRAM_0_BASE), i);

printf("%d,%d\n", i,value);

}

return 0;

}

but in the Console with result is only display 6 data:

0,16

16,16

32,16

48,16

64,16

80,16

Could anyone tell me where it is fault ?

At the SOPC Builder->More Settings->Exception Address & Memodule my setting is sdram_0. is this need change to sram_0 or not ? http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/blink.gif