CS-9302 External SDRAM and NOR Flash Access / Read-Write

Development Boards MicroMod
1

Hi,

I have a board of olimex CS 9302 which has booted linux 2.6 on ep9302.

I try to develop some code to reach external 32MB SDRAM and 16MB Nor Flash.

But i could not reach those memory spaces using mmap and open functions as below:

fd = open(”/dev/mem”, O_RDWR );

if (fd == -1) {

fprintf(stderr ,”\n%s\n”, “Cannot open /dev/mem device!”);

return(errno);

}

sdrambase = (unsigned int*) mmap(0, getpagesize(), PROT_READ|PROT_WRITE, \

MAP_SHARED, fd, 0xF0000000 );

(0xF0000000 : Base adress of SDRAM.)

Even though , ı didnt take segmentation fault error, ı couldnt change the values with the line below:

*sdrambase=0x01;

I can read those adress inclusion as

printf(“%u”,*sdrambase); but that value is not 1.

How can ı wite and read data to the external SDRAM or NOR flash on cs 9302 board.

Do you have an idea or sample code.

Thank you for helps.

2

what about this question ? was that so silly ? I couldn’t find any thing about the usage of external memory on ep 9302. No sample no idea? is writing or reading from sdram difficult job ?

thnx.