tmk_core/tool/mbed/mbed-sdk/libraries/mbed/common/Timer.cpp

   1 /* mbed Microcontroller Library
   2  * Copyright (c) 2006-2013 ARM Limited
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 #include "Timer.h"
  17 #include "us_ticker_api.h"
  18
  19 namespace mbed {
  20
  21 Timer::Timer() : _running(), _start(), _time() {
  22     reset();
  23 }
  24
  25 void Timer::start() {
  26     if (!_running) {
  27         _start = us_ticker_read();
  28         _running = 1;
  29     }
  30 }
  31
  32 void Timer::stop() {
  33     _time += slicetime();
  34     _running = 0;
  35 }
  36
  37 int Timer::read_us() {
  38     return _time + slicetime();
  39 }
  40
  41 float Timer::read() {
  42     return (float)read_us() / 1000000.0f;
  43 }
  44
  45 int Timer::read_ms() {
  46     return read_us() / 1000;
  47 }
  48
  49 int Timer::slicetime() {
  50     if (_running) {
  51         return us_ticker_read() - _start;
  52     } else {
  53         return 0;
  54     }
  55 }
  56
  57 void Timer::reset() {
  58     _start = us_ticker_read();
  59     _time = 0;
  60 }
  61
  62 #ifdef MBED_OPERATORS
  63 Timer::operator float() {
  64     return read();
  65 }
  66 #endif
  67
  68 } // namespace mbed