time.c

Philips LPC2200 Using External Program Memory

/******************************************************************************/
/*  This file is part of the uVision/ARM development tools                    */
/*  Copyright KEIL ELEKTRONIK GmbH 2002-2004                                  */
/******************************************************************************/
/*                                                                            */
/*  TIME.C:  Time Functions for 100Hz Clock Tick                              */
/*                                                                            */
/******************************************************************************/

#include <LPC22XX.H>                          // LPC22XX Peripheral Registers


long timeval;

/* Timer Counter 0 Interrupt executes each 10ms @ 60 MHz CPU Clock */
void tc0 (void) __irq {
  ++timeval;
  T0IR        = 1;                            // Clear interrupt flag
  VICVectAddr = 0;                            // Acknowledge Interrupt
}


/* Setup the Timer Counter 0 Interrupt */
void init_timer (void) {
  T0MR0 = 149999;                             // 10mSec = 150.000-1 counts
  T0MCR = 3;                                  // Interrupt and Reset on MR0
  T0TCR = 1;                                  // Timer0 Enable
  VICVectAddr0 = (unsigned long)tc0;          // set interrupt vector in 0
  VICVectCntl0 = 0x20 | 4;                    // use it for Timer 0 Interrupt
  VICIntEnable = 0x00000010;                  // Enable Timer0 Interrupt
}