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/* -*- c++ -*- */

/*

 * Copyright 2003 Free Software Foundation, Inc.

 *

 * This file is part of GNU Radio

 *

 * GNU Radio 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, or (at your option)

 * any later version.

 *

 * GNU Radio 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.

 *

 * You should have received a copy of the GNU General Public License

 * along with GNU Radio; see the file COPYING.  If not, write to

 * the Free Software Foundation, Inc., 51 Franklin Street,

 * Boston, MA 02110-1301, USA.

 */

/************************************************************************/

/** \file         timer.c

 ************************************************************************/

#include "timer.h"

#include "fx2regs.h"

#include "isr.h"

/**

 * Arrange to have isr_tick_handler called at 100 Hz.

 *

 * The cpu clock is running at 48e6.  The input to the timer

 * is 48e6 / 12 = 4e6.

 *

 * We arrange to have the timer overflow every 40000 clocks == 100 Hz

 */

#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;

  T2CON = 0x04;                 /* interrupt on overflow; reload; run */

  ET2 = 1;                      /* enable timer 2 interrupts */

}