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

> fp = fopen("C:\test1.txt", "w");

if you know where is "c:\" on your board?

when you just create CPU(NiosII)

you don't have file-system

you need to create file-system as well.( Linux, uC-OSII or by yourself).

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

Hi teddy,

--- Quote Start ---

p = fopen("C:\test1.txt", "w");

fprintf(fp, "%d", output_data);

fclose(fp);

--- Quote End ---

Akira is right. You need a filesystem for that.

But as Cris mentioned, I am also concerned about the IOWR/IORD-part.

If I got you right, you want to write input_data to some SDRAM-address and read it back for printing it.

First: I would let the compiler allocate memory for you, unless you know what is at the specified address. You can use malloc or something like that or you just declare a variable.

For example (assumed that data region is located at SDRAM):

#include <stdio.h># include <unistd.h># include "system.h"
int input_data = 1;
int output_data = 0;
int output_data_read = 0;
int main()
{
    IOWR(&output_data,0,input_data); // write input_data to output_data with IOWR
    output_data_read = IORD(&output_data,0); // read it back from output_data to output_data_read
    printf("output data = %d\n", output_data_read); // printing on STDOUT
   return 0;
}

Second: I would usually use IOWR/IORD only in cases where it can be neccessary. Like bypassing the data cache. Otherwise, better use standard C-coding for accessing memory.

Regards,

Philipp

--- Quote Start ---

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

--- Quote End ---

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;

}

=================================================

--- Quote Start ---

> fp = fopen("C:\test1.txt", "w");

if you know where is "c:\" on your board?

when you just create CPU(NiosII)

you don't have file-system

you need to create file-system as well.( Linux, uC-OSII or by yourself).

--- Quote End ---

Hi again!

Do you know how can I get from SDRAM data to my hard driver?

My goal is to have binary data of txt file form...

Thanks for your continuous concern.

Teddy,

0x prefix stands for hex number. One hex digit = 4bit !!!

You must use 0b00101... to specify a binary number.

Moreover, your 'long' data variables are actually 64bit long !

You are getting the correct 32bit prints with %x format.

If you want complete 64bit print you should use %lx or %llx

If you want ram native 16bit data access, you should define variables as 'short'.

Cris

--- Quote Start ---

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;

}

--- Quote End ---

I think it is not possible to perform 64 bit IOWR.

If you want to write 64 bit data you have to split it up into 2*IOWR.

Use IOWR twice.

Or am I wrong here? NIOS is 32bit

oh you are teddy80

hi again.

if you have UART(RS-232C)

you can program on NiosII to send data from SDRAM.

and your computer can get RS232C data some how like hyper terminal.

RS232C is slow...

there is several way. LAN / SD-Card / USB ...

but many things are difficult after all.

you need to learn more.

UART is easy to use.

I recommend biginer to use UART to read data from embedded system.

see you and good luck