HOW TO DETECT A RISING EDGE(OF A PULSE) ON NIOS 2 (ucLINUX) AS AN INTERRUPT

[Altera_Forum]

hi every one, 

i am using a nios 2(on cyclone 2) on uclinux os..can anybody suggest me ,how can i detect a rising or falling edge of a pulse(hardware signal) as an interrupt to the processor..??

[Altera_Forum]

you can use a PIO component for that.

[Altera_Forum]

thanks for reply... 

den is it required to keep on polling a perticular PIO pin using readh(0x40008df)memory loc..? how can i read it as an interrupt..??

[Altera_Forum]

Double click on it in SOPC builder. Then you can have it trigger an interrupt on level change.

[Altera_Forum]

but how will i come to know while executing my source code(in C) on processor.. 

i.e when i detect the signal, i should go to some routine(signal handler) in my C code.. what is the code sequence to do tat in c..

[Altera_Forum]

in the code there r instructions like 

  main() {  signal(SIGPIPE,SIG_IGN);  int fp,oflags;  signal(SIGIO, interrupt_handler);    fp = open("/dev/interrupt1", O_NOCTTY);  if(fp < 0)  {  printf("Error opening device node !\n");  }  else  {  fcntl(fp, F_SETOWN, getpid());  oflags = fcntl(fp, F_GETFL);  fcntl(fp, F_SETFL, oflags | FASYNC);  }  }///end of main function  interrupt_handler() {  \\control should come here when edge is detected }