Timer.h

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