Lpc2000

Hello guys!

I am starting my work with LPC2106. I made some leds flashing, now I am trying 
to understand how interrupts works. I could not find any documentation 
explining how to implement it using gcc, I have the Insiders Guide, but the 
examples are for the Keil only.
I made the program below, but the interrupt function are never called.
Can someone point my error? Or better, where can I get a documentation 
explaining how to implement interrupts with gcc?

Thanx in advance for any help.


My code:
In the ex_lpc_lib1.h, the variables are defined as below:
#define GPIO_IODIR   (*(t_reg32*)(0xE0028008))
#define PCB_PINSEL0   (*(t_reg32*)(0xE002C000))
#define VICIntSelect   (*(t_reg32*)(0xFFFFF00C))
#define VICIntEnable   (*(t_reg32*)(0xFFFFF010))
#define SCB_EXTINT   (*(t_reg32*)(0xE01FC140))

The program runs by flashing leds attached to pins P0.4 to P0.7 and P010 to 
P0.13. The DEBUGF is a macro that sends the string over JTAG. Pressing the 
button attached to EINT1 (this pin have a pull up resistor and the switch 
pulls the pin down) never go to the interrupcao() routine.
To compile this code, I had to make it as ARM, when I compiled it as THUMB I 
got an error saying that the FIQ routine must be compiled as ARM, so I 
compiled the entire code as ARM. Is it possible to tell to gcc that I want 
only the FIQ routine compiled as ARM?

#include "ex_lpc_lib1.h"
#define DEBUG_LEDS   0
#define DEBUG_OUT    1
#include "ex_debug.h"

static void delay(t_u32 wDelay);
static void escreve(t_u32 valor);
static void interrupcao() __attribute__ ((interrupt("FIQ"))) ;
/*------------------------------------------------------------------------------
 main
------------------------------------------------------------------------------*/

int main(void) {

	t_u32 escrita = 0x00000010;
	t_u32 x;

	GPIO_IODIR = 0x00003CF0;
	PCB_PINSEL0 = 0x20000000;
	VICIntSelect = 0x00008000;
	VICIntEnable = 0x00008000;
	
	
	for(;;) {
	
	for(x=4; x!=0; x--) {
		escreve(escrita);
		escrita = escrita << 1;
		}
	
	escrita = escrita << 2;
	
	for(x=3; x!=0; x--) {
		escreve(escrita);
		escrita = escrita << 1;
		}
		
	for(x=4; x!=0; x--) {
		escreve(escrita);
		escrita = escrita >> 1;
		}
	
	escrita = escrita >> 2;	
	
	for(x=3; x!=0; x--) {
		escreve(escrita);
		escrita = escrita >> 1;
		}			
		
		}	

   return 0;
}

void escreve(t_u32 valor) {

//	DEBUGF("Valor=%x\n", valor);
	GPIO_IOSET = valor;
	delay(100);
	GPIO_IOCLR = valor;
}
	

void delay(t_u32 wDelay) {
   t_u32 wClock;

// Gets current clock value and programs timer 0 to count in 1milisecond units

   wClock = ex_clock_get() * EX_BOARD_MCLOCK;
   T0_PR = (wClock / 1000) - 1;              // Prescale register
   T0_PC = 0;                                // Prescale counter
   T0_TC = 0;                                // Initialize timer counter
	T0_TCR = 1;                        	      // Enable counter

// Waits for counter value to reach specified value

   while (T0_TC < wDelay)
      ;
}

void __attribute__ ((interrupt("FIQ"))) interrupcao(void)  {

	DEBUGF("Interrompido\n");
	GPIO_IOSET = 0x00000010;
	SCB_EXTINT = 0x00000002;
	
	}