nios II--实验4——按键中断软件部分

/*

* "Hello World" example.

*

* This example prints ‘Hello from Nios II‘ to the STDOUT stream. It runs on

* the Nios II ‘standard‘, ‘full_featured‘, ‘fast‘, and ‘low_cost‘ example

* designs. It runs with or without the MicroC/OS-II RTOS and requires a STDOUT

* device in your system‘s hardware.

* The memory footprint of this hosted application is ~69 kbytes by default

* using the standard reference design.

*

* For a reduced footprint version of this template, and an explanation of how

* to reduce the memory footprint for a given application, see the

* "small_hello_world" template.

*

*/

?

#include <stdio.h>

#include "system.h"

#include "unistd.h"

#include "alt_types.h"

#include "altera_avalon_pio_regs.h"

#include "sys/alt_irq.h"

alt_u8 key_flag = 0;

void ISR_handle_button( void* context )

{

key_flag = ~key_flag;

printf("button interrupt!\n");

IOWR_ALTERA_AVALON_PIO_EDGE_CAP( BNT_PIO_BASE, 0x0 ); // clear the interrupt

}

void init_button_pio( void )

{

IOWR_ALTERA_AVALON_PIO_IRQ_MASK( BNT_PIO_BASE, 0x1 ); // 使能按钮中断

IOWR_ALTERA_AVALON_PIO_EDGE_CAP( BNT_PIO_BASE, 0x0 ); // 清边沿捕获寄存器

alt_ic_isr_register(BNT_PIO_IRQ_INTERRUPT_CONTROLLER_ID, BNT_PIO_IRQ, ISR_handle_button, NULL,0x0 );

}

int main()

{

int i;

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

init_button_pio();

for( i=0; i<4; i++ )

{

IOWR_ALTERA_AVALON_PIO_DATA( LED_PIO_BASE, 1<<i );

usleep( 10000 );//each one 0.5s delay

}

while(1)

{

if( key_flag )

{

IOWR_ALTERA_AVALON_PIO_DATA( LED_PIO_BASE, 1);

}

else

{

IOWR_ALTERA_AVALON_PIO_DATA( LED_PIO_BASE, 0);

}

}

return 0;

}