no_bsp/btimer/timerisr.c

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  *  @file
0005  *
0006  *  If required this ISR is used to bump a count of interval "overflow"
0007  *  interrupts which have occurred since the timer was started.  The
0008  *  number of overflows is taken into account in the benchmark_timer_read()
0009  *  routine if necessary.
0010  *
0011  *  To reduce overhead this is best to be the "rawest" hardware interupt
0012  *  handler you can write.  This should be the only interrupt which can
0013  *  occur during the measured time period.
0014  *
0015  *  @note This file is USUALLY in assembly and is LEAN AND MEAN.
0016  *        Any code in this isr is pure overhead which can perturb
0017  *        the accuracy of the Timing Test Suite.
0018  */
0019
0020 /*
0021  *  COPYRIGHT (c) 1989-1999.
0022  *  On-Line Applications Research Corporation (OAR).
0023  *
0024  * Redistribution and use in source and binary forms, with or without
0025  * modification, are permitted provided that the following conditions
0026  * are met:
0027  * 1. Redistributions of source code must retain the above copyright
0028  *    notice, this list of conditions and the following disclaimer.
0029  * 2. Redistributions in binary form must reproduce the above copyright
0030  *    notice, this list of conditions and the following disclaimer in the
0031  *    documentation and/or other materials provided with the distribution.
0032  *
0033  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0034  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0035  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0036  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0037  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0038  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0039  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0040  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0041  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0042  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0043  * POSSIBILITY OF SUCH DAMAGE.
0044  */
0045
0046 #include <rtems.h>
0047 #include <rtems/btimer.h>
0048
0049 extern uint32_t         _Timer_interrupts;
0050
0051 void timerisr( void )
0052 {
0053   /*
0054    *  _Timer_interrupts += TIMER_BETWEEN_OVERFLOWS  (usually in microseconds)
0055    *  return from interrupt
0056    */
0057 }