External Interrupt2 for LPC2148

EINT2 for LPC2148

//————————————————————————————————————————————————————————————————————————//
// Program : Example for EINT2(External interrupt2)
// Description : Test interrupt from switch press display by LED at P0.21
// : toggle and sound beep
// Frequency : Crystal 12 MHz at PLL 5x(CCLK = 60 MHz),PCLK = 30 MHz
// Filename : ext_int2.c
// C compiler : Keil CARM Compiler
//————————————————————————————————————————————————————————————————————————//
#include “lpc214x.h” // Header file for Phillips LPC2148 controller
#include “sound.h” // Header file for Phillips LPC2148 controller

//—————————————— Function for Initial system clock ————————————————//

void init()
{
PLL0CFG=0x24; // MSEL = 4,PSEL = 2
PLL0FEED=0xAA; // Feed process
PLL0FEED=0x55;
PLL0CON=0x1;
PLL0FEED=0xAA; // Feed process
PLL0FEED=0x55;
while(!(PLL0STAT & 0x400)) ; // Wait until PLL Locked
PLL0CON=0x3; // Connect the PLL as the clock source
PLL0FEED=0xAA; // Feed process
PLL0FEED=0x55;
MAMCR=0x2; // Enabling MAM and setting number of clocks used
// for Flash memory fetch (4 cclks in this case)
MAMTIM=0x4;
VPBDIV=0x02; // PCLK at 30 MHz
}

//—————————————— Interrupt service routine for EINT2 ———————————————//
void isr_int2(void) __irq
{
beep(); // Sound beep 1 time
FIO0PIN ^= (1<<21); // Toggle LED at P0.21
EXTINT |= 0x4; // Clear interrupt flag EINT2
VICVectAddr = 0; // Acknowledge Interrupt
}
//————————————————— Main Program ————————————————————————//
void main()
{
init(); // Initialize the system
SCS = 0x03; // select the “fast” version of the I/O ports
FIO0DIR |= (1<<21); // Config. output P0.21 connect LED
FIO0SET |= (1<<21); // OFF LED
EXTMODE |= 0x4; // EINT2 Edge sensitive detection
// (Falling edge in this program)
PINSEL0 = 0xC000; // Enable EINT2 at P0.7
VICVectAddr0 = (unsigned)isr_int2;
// Register Interrupt service routine name
VICVectCntl0 = 0x20 | 16; // EINT2 Interrupt
VICIntEnable |= 1 << 16; // Enable EINT2 Interrupt
while(1); // Infinite loop
}