source: rtems/c/src/lib/libbsp/m68k/gen68360/timer/timer.c @ b04a2b3

/*
 * Timer_init()
 *
 * Use TIMER 1 and TIMER 2 for Timing Test Suite
 *
 * The hardware on the MC68360 makes these routines very simple.
 *
 * Based on the `gen68302' board support package, and covered by the
 * original distribution terms.
 *
 * W. Eric Norum
 * Saskatchewan Accelerator Laboratory
 * University of Saskatchewan
 * Saskatoon, Saskatchewan, CANADA
 * eric@skatter.usask.ca
 *
 *  $Id$
 */

/*
 *
 *  Input parameters:  NONE
 *
 *  Output parameters:  NONE
 *
 *  NOTE: It is important that the timer start/stop overhead be 
 *        determined when porting or modifying this code.
 *
 *  COPYRIGHT (c) 1989-1999.
 *  On-Line Applications Research Corporation (OAR).
 *
 *  The license and distribution terms for this file may be
 *  found in the file LICENSE in this distribution or at
 *  http://www.rtems.com/license/LICENSE.
 */

#include <rtems.h>
#include <bsp.h>
#include "m68360.h"

void
Timer_initialize (void)
{
        /*
         * Reset timers 1 and 2
         */
        m360.tgcr &= ~0x00FF;
        m360.tcn1 = 0;
        m360.tcn2 = 0;
        m360.ter1 = 0xFFFF;
        m360.ter2 = 0xFFFF;

        /*
         * Cascade timers 1 and 2
         */
        m360.tgcr |= 0x0080;

        /*
         * Configure timers 1 and 2 to a single 32-bit, 1 MHz timer.
         * HARDWARE:
         *      Change the `25' to match your processor clock
         */
        m360.tmr2 = ((25-1) << 8) | 0x2;
        m360.tmr1 = 0;

        /*
         * Start the timers
         */
        m360.tgcr |=  0x0011;
}

/*
 * Return timer value in microsecond units
 */
int
Read_timer (void)
{
        return *(rtems_unsigned32 *)&m360.tcn1;
}

/*
 * Empty function call used in loops to measure basic cost of looping
 * in Timing Test Suite.
 */
rtems_status_code
Empty_function (void)
{
        return RTEMS_SUCCESSFUL;
}

void
Set_find_average_overhead(rtems_boolean find_flag)
{
}