source: rtems/cpukit/include/rtems/btimer.h @ 878487b0

5
Last change on this file since 878487b0 was 6b38b72f, checked in by Joel Sherrill <joel.sherrill@…>, on 03/15/15 at 15:30:28

cpukit/include/rtems/btimer.h: Improve brief

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Line 
1/**
2 * @file rtems/btimer.h
3 *
4 * @brief RTEMS Benchmark Timer API for all Boards
5 */
6
7/*
8 *  COPYRIGHT (c) 2011 Ralf Corsépius Ulm/Germany
9 *
10 *  Derived from libcsupport/include/timerdrv.h:
11 *
12 *  COPYRIGHT (c) 1989-1999.
13 *  On-Line Applications Research Corporation (OAR).
14 *
15 *  The license and distribution terms for this file may be
16 *  found in the file LICENSE in this distribution or at
17 *  http://www.rtems.org/license/LICENSE.
18 */
19
20/*
21 * All the functions declared as extern after this comment
22 * MUST be implemented in each BSP.
23 */
24
25#ifndef _RTEMS_BTIMER_H
26#define _RTEMS_BTIMER_H
27
28#include <stdbool.h>
29#include <stdint.h>
30#include <rtems/rtems/status.h>
31
32#ifdef __cplusplus
33extern "C" {
34#endif
35
36/**
37 * @defgroup BenchmarkTimer Benchmark Timer Driver Interface
38 *
39 * This module defines the interface for the Benchmark Timer Driver.
40 *
41 * The following methods in this module must be provided by each BSP:
42 *
43 *   - benchmark_timer_initialize
44 *   - benchmark_timer_read
45 *   - benchmark_timer_disable_subtracting_average_overhead
46 *
47 * The units measured are BSP specific but should be at the highest
48 * granularity possible.
49 *
50 * The Benchmark Timer may use the same hardware as the Clock Driver.
51 * No RTEMS Timing Tests will use both drivers at the same time.
52 */
53
54/**
55 * @brief This type is used to return a Benchmark Timer value.
56 *
57 * This type is used to contain benchmark times. The units are BSP specific.
58 */
59typedef uint32_t benchmark_timer_t;
60
61/**
62 * @brief Initialize the Benchmark Timer
63 *
64 * This method initializes the benchmark timer and resets it to begin
65 * counting.
66 */
67extern void benchmark_timer_initialize( void );
68
69/**
70 * @brief Read the Benchmark Timer
71 *
72 * This method stops the benchmark timer and returns the number of
73 * units that have passed since @a benchmark_timer_initialize was invoked.
74 *
75 * @return This method returns the number of units with the average overhead
76 *          removed. If the value is below the minimum trusted value, zero
77 *          is returned.
78 */
79extern benchmark_timer_t benchmark_timer_read( void );
80
81/**
82 * @brief Benchmark Timer Empty Function
83 *
84 * This method is used to determine loop overhead.
85 */
86extern rtems_status_code benchmark_timer_empty_function( void );
87
88/**
89 * @brief Disable Average Overhead Removal from the Benchmark Timer
90 *
91 * This method places the benchmark timer in a "raw" mode where it
92 * returns the actual number of units which have passed between
93 * calls to @a benchmark_timer_initialize and @a benchmark_timer_read
94 * counting.
95 *
96 * @param[in] find_flag indicates to enable or disable the mode
97 */
98extern void benchmark_timer_disable_subtracting_average_overhead(
99  bool find_flag
100);
101
102/**@}*/
103
104#ifdef __cplusplus
105}
106#endif
107
108#endif
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