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Altera_Forum
Honored Contributor I
830 Views

Interrupt code problem

Hi, 

 

Actually I am a beginner in using niosII. Currently I am having some trouble in trying the interrupt code. 

 

This is a simple interrupt code. I am using SW0 and SW1 as the buttons. 

 

But its not working.  

The output showing in nios2 console is just "none" 

no changes happening when I slide the switch. 

 

 

 

# include "alt_types.h"# include "altera_avalon_pio_regs.h"# include "sys/alt_irq.h"# include "system.h"# include <stdio.h># include <unistd.h> 

 

 

/* A variable to hold the value of the button pio edge capture register. */ 

volatile int edge_capture; 

int count = 0; 

 

 

int handle_interrupt(); 

 

# ifdef PIO_1_BASE 

static void handle_button_interrupts(void* context, alt_u32 id) 

 

volatile int* edge_capture_ptr = (volatile int*) context; 

*edge_capture_ptr = IORD_ALTERA_AVALON_PIO_EDGE_CAP(PIO_1_BASE); 

count += handle_interrupt(*edge_capture_ptr); 

printf ("Total count = %d\n", count); 

IOWR_ALTERA_AVALON_PIO_EDGE_CAP(PIO_1_BASE, 0); 

/* Initialize the button_pio. */ 

static void init_button_pio() 

 

 

 

volatile void* edge_capture_ptr = (void *) &edge_capture; 

IOWR_ALTERA_AVALON_PIO_IRQ_MASK(PIO_1_BASE, 0xf); 

IOWR_ALTERA_AVALON_PIO_EDGE_CAP(PIO_1_BASE, 0x0); 

alt_irq_register( PIO_1_IRQ, edge_capture_ptr, 

handle_button_interrupts ); 

 

 

 

# endif 

 

 

static void initial_message() 

printf("\n\n**************************\n"); 

printf("* Hello from Nios II! *\n"); 

printf("**************************\n"); 

 

 

int main(void) 

 

 

/* Initialize the button pio. */ 

 

# ifdef PIO_1_BASE 

init_button_pio();# endif 

 

 

alt_irq_enable_all(PIO_1_IRQ); 

/* Initial message to output. */ 

 

 

initial_message(); 

 

 

/* Continue counting loop. */ 

 

 

while( 1 ) 

usleep(100000); 

if(edge_capture!=0) 

handle_interrupt(edge_capture); 

else 

printf("none \n"); 

return 0; 

 

 

int handle_interrupt(int button) 

switch (button) 

case 0x1: 

printf("Button 1"); 

return 1; 

break; 

case 0x2: 

printf( "Button 2 \n"); 

return 2; 

break; 

case 0x3: 

printf( "Both 3\n"); 

return 3; 

break; 

default: 

printf( "Button press 0x%x UNKNOWN!!\n", button); 

return 0; 

break; 

 

 

 

 

 

Can anyone help me out?? 

 

Thanks in advance.
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2 Replies
Altera_Forum
Honored Contributor I
28 Views

Hi, maybe in you interrupt function, you should write  

IOWR_ALTERA_AVALON_PIO_EDGE_CAP(PIO_1_BASE, 1); 

 

Avoid printf() in interrupts 

 

Here, you could post your code within [ code] balises 

 

(Instead of printf(), you could light up some LEDs)
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