NIOS II C language about SDRAM IOWR & IORD function and fopen & fclose

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Hi Teddy,

Apart from the fopen issue, I'm concerned about the two R/W instructions:

IOWR(SDRAM_0_BASE, 0, input_data);
 output_data = IORD(SDRAM_0_BASE, input_data);

Problem 1:

You are writing to address 0 and reading from address 1 (content of input_data) which has not been initialized.

Maybe, you meant this:

output_data = IORD(SDRAM_0_BASE, 0);

Problem 2:

Are you sure this part of sdram is not already used for anything else?

Otherwise your IOWR would corrupt code or other data.

Cris

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Thanks for your answer.

I used 16bit input_data in c code and

16bit SDRAM using SOPC Builder,

but I got only 8bit output_data.

Where is the problem?

<result>

output data1 = 11111111

output data2 = 10101010

=================================================# include <stdio.h># include <unistd.h># include "system.h"

int main()

{

long input_data1 = 0x0000000011111111;

long input_data2 = 0x1010101010101010;

long output_data1;

long output_data2;

IOWR(SDRAM_0_BASE, 0, input_data1);

output_data1 = IORD(SDRAM_0_BASE, 0);

printf("output data1 = %x\n", output_data1);

IOWR(SDRAM_0_BASE + 1, 0, input_data2);

output_data2 = IORD(SDRAM_0_BASE + 1, 0);

printf("output data2 = %x\n", output_data2);

return 0;

}

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