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Altera_Forum
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17 years ago

Easy nios II design

Hello, I am a newbie with Quartus II and Nios II and I have been trying to do an easy nios design in order to light on a led when pressing a button. I am working on the Altera Cyclone III EP3C2...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
17 years ago

Hi Myriam,

Without getting into a discussion about better ways of handling buttons, here are some changes that should get your code doing what you expected it to do:

# include "system.h"# include "altera_avalon_pio_regs.h"# include "alt_types.h"# include "stdio.h"# include "stdlib.h"

int alt_main (void)

{

alt_u8 led;

alt_u8 button;

while (1)

{

button = IORD_ALTERA_AVALON_PIO_DATA(BUTTON_PIO_BASE);

switch (button) {

case 0x1 :

led=0x1;

break;

case 0x2 :

led=0x2;

break;

case 0x4 :

led=0x4;

break;

case 0x8 :

led=0x8;

break;

}

IOWR_ALTERA_AVALON_PIO_DATA(LED_PIO_BASE, led);

}

Note that the button PIO is read with an IORD_ function call.

I imagine your problem with printf is that you do not have a device configured for stdout.