Interrupt on my radar application - what have I been programming ?

Dear Forum users,

I implemented with verilog a simple 32 bit wide COUNTER. Then I read the counter out with

Nios and I implemented on my radar application two switches - one switch for starting the

radar pulse and one switch for displaying the result on the RS232. Now the code it functions

but I do not know what I have been implementing with version 9.1.

The code will look as follows:

//PAVLE DUKANOVIC

//www.dukelanovic.com

//Neckarrems,19.10.2014

//

//RS232 COMMUNICATIONS

//

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

# define seg *(volatile unsigned char *) SEG_BASE # define bit *(volatile unsigned char *) BIT_BASE # define RESET *(volatile unsigned char *) RESET_BASE# define TRIG *(volatile unsigned char *) TRIG_BASE# define COUNTER *(volatile alt_u32 *) COUNTER_BASE# define START *(volatile alt_u32 *) START_BASE

const alt_u8 duan[10]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90};

// 0 1 2 3 4 5 6 7 8 9

alt_u8 num[8] = {0,0,0,0,0,0,0,0};

alt_u8 number[8];

alt_u32 n = 0;

alt_u8 key_flag;

alt_u8 key_flag1;

volatile int edge_capture;

void key_ISR(void* context, alt_u32 id)

{

IOWR_ALTERA_AVALON_PIO_EDGE_CAP(START_BASE,0);

IORD_ALTERA_AVALON_PIO_EDGE_CAP(START_BASE);

key_flag = 1;

}

void key3_ISR(void* context, alt_u32 id)

{

IOWR_ALTERA_AVALON_PIO_EDGE_CAP(K3_BASE,0);

IORD_ALTERA_AVALON_PIO_EDGE_CAP(K3_BASE);

key_flag1 = 1;

}

void key_Init()

{

IOWR_ALTERA_AVALON_PIO_IRQ_MASK(START_BASE,0xF);

IOWR_ALTERA_AVALON_PIO_EDGE_CAP(START_BASE,0x0);

alt_irq_register(START_IRQ,NULL,key_ISR); //START_IRQ 3

}

void key3_Init()

{

IOWR_ALTERA_AVALON_PIO_IRQ_MASK(K3_BASE,0xF);

IOWR_ALTERA_AVALON_PIO_EDGE_CAP(K3_BASE,0x0);

alt_irq_register(K3_IRQ,NULL,key3_ISR); //START_IRQ 3

}

// This function will display 8 Numbers

void display(alt_u32 i)

{

alt_u8 j;

num[0] = ((((((i % 10000000)%1000000)%100000)%10000)%1000)%100)%10;

num[1] = ((((((i % 10000000)%1000000)%100000)%10000)%1000)%100)/10;

num[2] = (((((i % 10000000)%1000000)%100000)%10000)%1000)/100;

num[3] = ((((i % 10000000)%1000000)%100000)%10000)/1000;

num[4] = (((i % 10000000)%1000000)%100000)/10000;

num[5] = ((i % 10000000)%1000000)/100000;

num[6] = (i % 10000000)/1000000;

num[7] = i / 10000000;

for(j=0; j<8; j++)

{

bit = ~(0x01 << j);

seg = duan[num[j]]; // here the display is switched on

usleep(100);

}

number[7] = ((((((i % 10000000)%1000000)%100000)%10000)%1000)%100)%10+0x30;

number[6] = ((((((i % 10000000)%1000000)%100000)%10000)%1000)%100)/10+0x30;

number[5] = (((((i % 10000000)%1000000)%100000)%10000)%1000)/100+0x30;

number[4] = ((((i % 10000000)%1000000)%100000)%10000)/1000+0x30;

number[3] = (((i % 10000000)%1000000)%100000)/10000+0x30;

number[2] = ((i % 10000000)%1000000)/100000+0x30;

number[1] = (i % 10000000)/1000000+0x30;

number[0] = i / 10000000+0x30;

}

int main ()

{

char* msg = "M01 ";

FILE* fp;

key_Init();

key3_Init();

printf("RS232 DEMO : \n");

fp = fopen (UART_NAME, "r+"); // here we initialize the RS232 port

RESET = 1;

TRIG =1;

while(1){

n = COUNTER;

display(n);

usleep(100);

if(key_flag){

TRIG = 0;

usleep(10);

fwrite (msg, strlen (msg), 1, fp); // here we write on the RS232

usleep(40000);

key_flag = 0;

TRIG = 1;

}

if(key_flag1){

fwrite (number, strlen (number), 1, fp); // here we write on the RS232

key_flag1 = 0;

}

}

return 0;

}

Can you tell me where I can find a good reference about programming and handling interrupts?

What have I been doing with the initialisation of my interrupt?

void key_Init()

{

IOWR_ALTERA_AVALON_PIO_IRQ_MASK(START_BASE,0xF);

IOWR_ALTERA_AVALON_PIO_EDGE_CAP(START_BASE,0x0);

alt_irq_register(START_IRQ,NULL,key_ISR); //START_IRQ 3

}

What do those commands mean ?

Please help me.