Timer.cpp

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 #include "Timer.h"
00017 #include "us_ticker_api.h"
00018 
00019 namespace mbed {
00020 
00021 Timer::Timer() : _running(), _start(), _time() {
00022     reset();
00023 }
00024 
00025 void Timer::start() {
00026     if (!_running) {
00027         _start = us_ticker_read();
00028         _running = 1;
00029     }
00030 }
00031 
00032 void Timer::stop() {
00033     _time += slicetime();
00034     _running = 0;
00035 }
00036 
00037 int Timer::read_us() {
00038     return _time + slicetime();
00039 }
00040 
00041 float Timer::read() {
00042     return (float)read_us() / 1000000.0f;
00043 }
00044 
00045 int Timer::read_ms() {
00046     return read_us() / 1000;
00047 }
00048 
00049 int Timer::slicetime() {
00050     if (_running) {
00051         return us_ticker_read() - _start;
00052     } else {
00053         return 0;
00054     }
00055 }
00056 
00057 void Timer::reset() {
00058     _start = us_ticker_read();
00059     _time = 0;
00060 }
00061 
00062 #ifdef MBED_OPERATORS
00063 Timer::operator float() {
00064     return read();
00065 }
00066 #endif
00067 
00068 } // namespace mbed