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Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

Switch on leds on DE2

Hey, im trying to switch on LEds on DE2.

http://thalandinenop99.free.fr/image.jpg

You can see here the system that i've generated.

Leds is set in output with 8 bits and Switch set in input with 8 bits

I've generated the system then i've programmed it to my DE2, then i've written this code in C with NIOS 2 IDE in oder to switch on the LED :

# define SWITCHES_BASE_ADDRESS 0x00009010# define LEDR_BASE_ADDRESS 0x00009000

int main(void)

{

int * red_leds = (int *) LEDR_BASE_ADDRESS; /* red_leds is a pointer to the LEDRs */

volatile int * Switch = (int *) SWITCHES_BASE_ADDRESS; /* switches point to toggle switches */

printf("Hello from Nios II!\n");

while(1)

{

*(red_leds) = *(Switch); /* Red LEDR[k] is set equal to SW[k] */

}

return 0;

}

i've send this to DE2. i don't understand why, LED's doesn't want to switch on....any idea ?? is there any turorial of how i have to code in C if yes, where can i download this file...could you plus help me to solve this problem.

Thanks

2 Replies

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

    If you have used Nios II full version, addresses below to 0x8000000 are cacheable, so you will experience problems accesing hardware in the way you're doing. I strongly suggest use the IORD and IOWR macros, they use I/O instructions. So according to your SOPC system 

    
# include "system.h"
# include "io.h"
...
while(1)
{
IOWR(LEDS_BASE,0,IORD(SWITCH_BASE,0));
}
......

    base address definitions are made on "system.h".