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Can't get interrupt to work

Hi, I am sorry if there is already a thread open with this problem, I just couldn't find it.

I have a problem which should be easy to solve for you guys. I am trying to get a simple interrupt service routine to run, when i press the INT0 button on a MCB2300 Board (LPC2368). I didn't chance the startup.s code at all. When I press the button, nothing happens. Please help me.

#include <LPC23xx.h>

int main(void) {

PINSEL10 = 0;
FIO2DIR  = 0x000000FF;
FIO2MASK = 0x00000000;
FIO2CLR = 0xFF;
FIO2SET =  0x55;

VICIntSelect = 0x00008000;
VICIntEnable = 0x00008000;


while(1){

}
return 0;
}


int i;

void __irq FIQ_Handler (void)  {
        FIO2DIR  = 0x000000FF;
        FIO2MASK = 0x00000000;
        //Here goes the interrupt
        for ( i = 0; i <10000; i++) {
                FIO2CLR = 0xFF;
                FIO2SET =       0xAA;
        }
        FIO2CLR = 0xFF;
        VICVectAddr = 0x00000000;
}

Parents

0 Paul Radke over 15 years ago in reply to ImPer Westermark

Hi, I tried to change the code but it didn't work. So I looked around a bit and tried to find a solution but all I found didn't work.

I now use code I found on the internet and changed a bit but still, nothing.

I know my code wasn't exactly what one would call beautiful, it was just for testing, nothing to keep for later.

So can anyone tell me whats wrong here?

#include <stdio.h>
#include <LPC23xx.H>


void initialize_leds (void)
{
  FIO2DIR  = 0x000000FF;            // Define P2.0 through P2.7 as Outputs
  FIO2MASK = 0x00000000;
}

void set_led(unsigned int value)
{
  FIO2CLR = 0xFF;
  FIO2SET = (value & 0xFF);
}

volatile int led_state = 0;

void isr_handler_eint0(void) __irq // for external interrupt 0
{
        VICIntEnClr = (1 << 14); // Disable EINT0 in the VIC

        //this causes the leds to light up in sequence
        led_state = ( led_state << 1 ) | 1;

        //if all leds are lit up, turn them all off
        if( led_state > 0xFF)
                led_state = 0;

        set_led(led_state);

        //EXTPOLAR = 1; // next interrupt on rising edge

        EXTINT = 0x01; // Clear the peripheral interrupt flag
        VICIntEnable = (1 << 14); // Enable EINT0 in the VIC
        VICVectAddr = 0; // Acknowledge Interrupt
}


void initialize_eint0 (void)
{
        // P2.10 as EINT0 interrupt    (push button on MCB2300)
        PINSEL4 |= 0x01 << 20;
        // EINT0 is (falling) edge-sensitive
        EXTMODE = 0x01;
        // assign our ISR handler function to this VIC address
        VICVectAddr14 = (unsigned) isr_handler_eint0;
        // Interrupt on the falling edge (should default to 0)
        EXTPOLAR = 0x00;

        // Clear the peripheral interrupt flag
        EXTINT = 0x01;
        // Enable EINT0
        VICIntEnable = (1 << 14);
}



__inline void enable_IRQ(void)
{
int tmp;
    __asm
    {
        MRS tmp, CPSR
        BIC tmp, tmp, #0x80
        MSR CPSR_c, tmp
    }
}

__inline void enable_FIQ(void)
{
int tmp;
    __asm
    {
        MRS tmp, CPSR
        BIC tmp, tmp, #0x40
        MSR CPSR_c, tmp
    }
}

int main (void)
{
        enable_IRQ();
        enable_FIQ();

        PINSEL10 = 0;                   // Disable ETM interface

        initialize_leds();              // Init LEDS

        initialize_eint0();             // Init EINT0

        while (1)
        {
                // ... do nothing
        }

}

Reply

0 Paul Radke over 15 years ago in reply to ImPer Westermark

Hi, I tried to change the code but it didn't work. So I looked around a bit and tried to find a solution but all I found didn't work.

I now use code I found on the internet and changed a bit but still, nothing.

I know my code wasn't exactly what one would call beautiful, it was just for testing, nothing to keep for later.

So can anyone tell me whats wrong here?

#include <stdio.h>
#include <LPC23xx.H>


void initialize_leds (void)
{
  FIO2DIR  = 0x000000FF;            // Define P2.0 through P2.7 as Outputs
  FIO2MASK = 0x00000000;
}

void set_led(unsigned int value)
{
  FIO2CLR = 0xFF;
  FIO2SET = (value & 0xFF);
}

volatile int led_state = 0;

void isr_handler_eint0(void) __irq // for external interrupt 0
{
        VICIntEnClr = (1 << 14); // Disable EINT0 in the VIC

        //this causes the leds to light up in sequence
        led_state = ( led_state << 1 ) | 1;

        //if all leds are lit up, turn them all off
        if( led_state > 0xFF)
                led_state = 0;

        set_led(led_state);

        //EXTPOLAR = 1; // next interrupt on rising edge

        EXTINT = 0x01; // Clear the peripheral interrupt flag
        VICIntEnable = (1 << 14); // Enable EINT0 in the VIC
        VICVectAddr = 0; // Acknowledge Interrupt
}


void initialize_eint0 (void)
{
        // P2.10 as EINT0 interrupt    (push button on MCB2300)
        PINSEL4 |= 0x01 << 20;
        // EINT0 is (falling) edge-sensitive
        EXTMODE = 0x01;
        // assign our ISR handler function to this VIC address
        VICVectAddr14 = (unsigned) isr_handler_eint0;
        // Interrupt on the falling edge (should default to 0)
        EXTPOLAR = 0x00;

        // Clear the peripheral interrupt flag
        EXTINT = 0x01;
        // Enable EINT0
        VICIntEnable = (1 << 14);
}



__inline void enable_IRQ(void)
{
int tmp;
    __asm
    {
        MRS tmp, CPSR
        BIC tmp, tmp, #0x80
        MSR CPSR_c, tmp
    }
}

__inline void enable_FIQ(void)
{
int tmp;
    __asm
    {
        MRS tmp, CPSR
        BIC tmp, tmp, #0x40
        MSR CPSR_c, tmp
    }
}

int main (void)
{
        enable_IRQ();
        enable_FIQ();

        PINSEL10 = 0;                   // Disable ETM interface

        initialize_leds();              // Init LEDS

        initialize_eint0();             // Init EINT0

        while (1)
        {
                // ... do nothing
        }

}

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