Johannes Stratmann / mbed-dev

added prescaler for 16 bit pwm in LPC1347 target

Fork of mbed-dev by mbed official

common/Timer.cpp@147:ba84b7dc41a7, 2016-09-10 (annotated)

Committer:
JojoS
Date:
Sat Sep 10 15:32:04 2016 +0000
Revision:
147:ba84b7dc41a7
Parent:
144:ef7eb2e8f9f7 
added prescaler for 16 bit timers (solution as in LPC11xx), default prescaler 31 for max 28 ms period time

Who changed what in which revision?

UserRevisionLine numberNew contents of line
<> 144:ef7eb2e8f9f7 1 /* mbed Microcontroller Library
<> 144:ef7eb2e8f9f7 2 * Copyright (c) 2006-2013 ARM Limited
<> 144:ef7eb2e8f9f7 3 *
<> 144:ef7eb2e8f9f7 4 * Licensed under the Apache License, Version 2.0 (the "License");
<> 144:ef7eb2e8f9f7 5 * you may not use this file except in compliance with the License.
<> 144:ef7eb2e8f9f7 6 * You may obtain a copy of the License at
<> 144:ef7eb2e8f9f7 7 *
<> 144:ef7eb2e8f9f7 8 * http://www.apache.org/licenses/LICENSE-2.0
<> 144:ef7eb2e8f9f7 9 *
<> 144:ef7eb2e8f9f7 10 * Unless required by applicable law or agreed to in writing, software
<> 144:ef7eb2e8f9f7 11 * distributed under the License is distributed on an "AS IS" BASIS,
<> 144:ef7eb2e8f9f7 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
<> 144:ef7eb2e8f9f7 13 * See the License for the specific language governing permissions and
<> 144:ef7eb2e8f9f7 14 * limitations under the License.
<> 144:ef7eb2e8f9f7 15 */
<> 144:ef7eb2e8f9f7 16 #include "Timer.h"
<> 144:ef7eb2e8f9f7 17 #include "ticker_api.h"
<> 144:ef7eb2e8f9f7 18 #include "us_ticker_api.h"
<> 144:ef7eb2e8f9f7 19 #include "critical.h"
<> 144:ef7eb2e8f9f7 20
<> 144:ef7eb2e8f9f7 21 namespace mbed {
<> 144:ef7eb2e8f9f7 22
<> 144:ef7eb2e8f9f7 23 Timer::Timer() : _running(), _start(), _time(), _ticker_data(get_us_ticker_data()) {
<> 144:ef7eb2e8f9f7 24 reset();
<> 144:ef7eb2e8f9f7 25 }
<> 144:ef7eb2e8f9f7 26
<> 144:ef7eb2e8f9f7 27 Timer::Timer(const ticker_data_t *data) : _running(), _start(), _time(), _ticker_data(data) {
<> 144:ef7eb2e8f9f7 28 reset();
<> 144:ef7eb2e8f9f7 29 }
<> 144:ef7eb2e8f9f7 30
<> 144:ef7eb2e8f9f7 31 void Timer::start() {
<> 144:ef7eb2e8f9f7 32 core_util_critical_section_enter();
<> 144:ef7eb2e8f9f7 33 if (!_running) {
<> 144:ef7eb2e8f9f7 34 _start = ticker_read(_ticker_data);
<> 144:ef7eb2e8f9f7 35 _running = 1;
<> 144:ef7eb2e8f9f7 36 }
<> 144:ef7eb2e8f9f7 37 core_util_critical_section_exit();
<> 144:ef7eb2e8f9f7 38 }
<> 144:ef7eb2e8f9f7 39
<> 144:ef7eb2e8f9f7 40 void Timer::stop() {
<> 144:ef7eb2e8f9f7 41 core_util_critical_section_enter();
<> 144:ef7eb2e8f9f7 42 _time += slicetime();
<> 144:ef7eb2e8f9f7 43 _running = 0;
<> 144:ef7eb2e8f9f7 44 core_util_critical_section_exit();
<> 144:ef7eb2e8f9f7 45 }
<> 144:ef7eb2e8f9f7 46
<> 144:ef7eb2e8f9f7 47 int Timer::read_us() {
<> 144:ef7eb2e8f9f7 48 core_util_critical_section_enter();
<> 144:ef7eb2e8f9f7 49 int time = _time + slicetime();
<> 144:ef7eb2e8f9f7 50 core_util_critical_section_exit();
<> 144:ef7eb2e8f9f7 51 return time;
<> 144:ef7eb2e8f9f7 52 }
<> 144:ef7eb2e8f9f7 53
<> 144:ef7eb2e8f9f7 54 float Timer::read() {
<> 144:ef7eb2e8f9f7 55 return (float)read_us() / 1000000.0f;
<> 144:ef7eb2e8f9f7 56 }
<> 144:ef7eb2e8f9f7 57
<> 144:ef7eb2e8f9f7 58 int Timer::read_ms() {
<> 144:ef7eb2e8f9f7 59 return read_us() / 1000;
<> 144:ef7eb2e8f9f7 60 }
<> 144:ef7eb2e8f9f7 61
<> 144:ef7eb2e8f9f7 62 int Timer::slicetime() {
<> 144:ef7eb2e8f9f7 63 core_util_critical_section_enter();
<> 144:ef7eb2e8f9f7 64 int ret = 0;
<> 144:ef7eb2e8f9f7 65 if (_running) {
<> 144:ef7eb2e8f9f7 66 ret = ticker_read(_ticker_data) - _start;
<> 144:ef7eb2e8f9f7 67 }
<> 144:ef7eb2e8f9f7 68 core_util_critical_section_exit();
<> 144:ef7eb2e8f9f7 69 return ret;
<> 144:ef7eb2e8f9f7 70 }
<> 144:ef7eb2e8f9f7 71
<> 144:ef7eb2e8f9f7 72 void Timer::reset() {
<> 144:ef7eb2e8f9f7 73 core_util_critical_section_enter();
<> 144:ef7eb2e8f9f7 74 _start = ticker_read(_ticker_data);
<> 144:ef7eb2e8f9f7 75 _time = 0;
<> 144:ef7eb2e8f9f7 76 core_util_critical_section_exit();
<> 144:ef7eb2e8f9f7 77 }
<> 144:ef7eb2e8f9f7 78
<> 144:ef7eb2e8f9f7 79 Timer::operator float() {
<> 144:ef7eb2e8f9f7 80 return read();
<> 144:ef7eb2e8f9f7 81 }
<> 144:ef7eb2e8f9f7 82
<> 144:ef7eb2e8f9f7 83 } // namespace mbed