M:/USB-BDI/USB-BDI/Firmware/MPC555-USB-BDI/lib/timer.c

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/*      USB-BDI Used for programming and debugging a MPC555 over USB
 * 
 *  Copyright 2005 NTB Interstate University of Applied Sciences of Technology Buchs
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 */

#include "timer.h"
#include "fx2regs.h"
#include "isr.h"

#define RELOAD_VALUE    ((unsigned short) -40000)

void hook_timer_tick (unsigned short isr_tick_handler){
        ET2 = 0;                        // disable timer 2 interrupts
        hook_sv (SV_TIMER_2, isr_tick_handler);
  
        RCAP2H = RELOAD_VALUE >> 8;     // setup the auto reload value
        RCAP2L = RELOAD_VALUE & 0x00FF;

        T2CON = 0x04;                   // interrupt on overflow; reload; run
        ET2 = 1;                        // enable timer 2 interrupts
}