Timer.h

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2006-2013 ARM Limited
00003  * SPDX-License-Identifier: Apache-2.0
00004  *
00005  * Licensed under the Apache License, Version 2.0 (the "License");
00006  * you may not use this file except in compliance with the License.
00007  * You may obtain a copy of the License at
00008  *
00009  *     http://www.apache.org/licenses/LICENSE-2.0
00010  *
00011  * Unless required by applicable law or agreed to in writing, software
00012  * distributed under the License is distributed on an "AS IS" BASIS,
00013  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00014  * See the License for the specific language governing permissions and
00015  * limitations under the License.
00016  */
00017 #ifndef MBED_TIMER_H
00018 #define MBED_TIMER_H
00019 
00020 #include "platform/platform.h"
00021 #include "hal/ticker_api.h"
00022 #include "platform/NonCopyable.h"
00023 #include "platform/mbed_power_mgmt.h"
00024 
00025 namespace mbed {
00026 /** \addtogroup drivers */
00027 
00028 /** A general purpose timer
00029  *
00030  * @note Synchronization level: Interrupt safe
00031  *
00032  * Example:
00033  * @code
00034  * // Count the time to toggle an LED
00035  *
00036  * #include "mbed.h"
00037  *
00038  * Timer timer;
00039  * DigitalOut led(LED1);
00040  * int begin, end;
00041  *
00042  * int main() {
00043  *     timer.start();
00044  *     begin = timer.read_us();
00045  *     led = !led;
00046  *     end = timer.read_us();
00047  *     printf("Toggle the led takes %d us", end - begin);
00048  * }
00049  * @endcode
00050  * @ingroup drivers
00051  */
00052 class Timer : private NonCopyable<Timer> {
00053 
00054 public:
00055     Timer();
00056     Timer(const ticker_data_t *data);
00057     ~Timer();
00058 
00059     /** Start the timer
00060      */
00061     void start();
00062 
00063     /** Stop the timer
00064      */
00065     void stop();
00066 
00067     /** Reset the timer to 0.
00068      *
00069      * If it was already running, it will continue
00070      */
00071     void reset();
00072 
00073     /** Get the time passed in seconds
00074      *
00075      *  @returns    Time passed in seconds
00076      */
00077     float read();
00078 
00079     /** Get the time passed in milliseconds
00080      *
00081      *  @returns    Time passed in milliseconds
00082      */
00083     int read_ms();
00084 
00085     /** Get the time passed in microseconds
00086      *
00087      *  @returns    Time passed in microseconds
00088      */
00089     int read_us();
00090 
00091     /** An operator shorthand for read()
00092      */
00093     operator float();
00094 
00095     /** Get in a high resolution type the time passed in microseconds.
00096      *  Returns a 64 bit integer.
00097      */
00098     us_timestamp_t read_high_resolution_us();
00099 
00100 #if !defined(DOXYGEN_ONLY)
00101 protected:
00102     us_timestamp_t slicetime();
00103     int _running;            // whether the timer is running
00104     us_timestamp_t _start;   // the start time of the latest slice
00105     us_timestamp_t _time;    // any accumulated time from previous slices
00106     const ticker_data_t *_ticker_data;
00107     bool _lock_deepsleep;    // flag that indicates if deep sleep should be disabled
00108 };
00109 #endif
00110 
00111 } // namespace mbed
00112 
00113 #endif