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Altera_Forum's avatar
Altera_Forum
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11 years ago

NIOS II CustomComponent Programming Problem

Hi all,

I have created a LED register in vhdl and created qsys component out of that. Connected it to the nios processor as shown in below images. Created NIOS project and when I am trying to run the code the register is not updated. But if I access with the base address of the memory map generated, it is getting updated. Kindly someone let me know what could be the issue.

I included system.h and written a simple program to edit the led base register. From memory I am able to access and blink led. But from C program I am not able to control it.

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

int main()

{

unsigned int* ledbaseaddr =(unsigned int *) LEDREG_0_BASE;

// unsigned int i;

while(1)

{

*ledbaseaddr = 0xFF;

//for(i=0;i<100;i++);

*ledbaseaddr = 0x00;

}

}

http://www.alteraforum.com/forum/attachment.php?attachmentid=10302&stc=1 http://www.alteraforum.com/forum/attachment.php?attachmentid=10300&stc=1

http://www.alteraforum.com/forum/attachment.php?attachmentid=10301&stc=1 http://www.alteraforum.com/forum/attachment.php?attachmentid=10302&stc=1

Regards,

Phaniendra

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    11 years ago

    I guess this happens because Nios uses byte addressing, while C code unsigned int* forces 32bit addressing. Try to cast with unsigned char* .

    Anyway the best way to access qsys component registers is through IOWR/IORD macros, which automatically take care of matching the device bus size.
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    11 years ago

    Hi cris,

    thanks for the reply. I have used IOWR/IORD macros and problem got solved.