mbed library sources
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targets/hal/TARGET_STM/TARGET_NUCLEO_F302R8/us_ticker.c@304:89b9c3a9a045, 2014-08-29 (annotated)
- Committer:
- mbed_official
- Date:
- Fri Aug 29 17:15:07 2014 +0100
- Revision:
- 304:89b9c3a9a045
- Parent:
- 135:067cc8ba23da
Synchronized with git revision 734f365d7da26ef199751f4b0d91611479b495ea
Full URL: https://github.com/mbedmicro/mbed/commit/734f365d7da26ef199751f4b0d91611479b495ea/
1. timestamp_t as an abstraction for time values managed by
Ticker. Using uint64_t for timestamp_t allows a wraparound-free
Ticker. This change forces us to update the definitions of usTicker
for all platforms; but the changes beyond nRF51822 aren't major.
2. reduce power consumption on the nRF51822 by removing the need for
the high-frequency processor timer; and reimplementing it using the
RTC.
I've also replaced high-frequency clock with low-frequency external
clock during system startup of the nRF51822. This brings a major win
in power consumption.
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
mbed_official | 125:23cc3068a9e4 | 1 | /* mbed Microcontroller Library |
mbed_official | 125:23cc3068a9e4 | 2 | * Copyright (c) 2014, STMicroelectronics |
mbed_official | 125:23cc3068a9e4 | 3 | * All rights reserved. |
mbed_official | 125:23cc3068a9e4 | 4 | * |
mbed_official | 125:23cc3068a9e4 | 5 | * Redistribution and use in source and binary forms, with or without |
mbed_official | 125:23cc3068a9e4 | 6 | * modification, are permitted provided that the following conditions are met: |
mbed_official | 125:23cc3068a9e4 | 7 | * |
mbed_official | 125:23cc3068a9e4 | 8 | * 1. Redistributions of source code must retain the above copyright notice, |
mbed_official | 125:23cc3068a9e4 | 9 | * this list of conditions and the following disclaimer. |
mbed_official | 125:23cc3068a9e4 | 10 | * 2. Redistributions in binary form must reproduce the above copyright notice, |
mbed_official | 125:23cc3068a9e4 | 11 | * this list of conditions and the following disclaimer in the documentation |
mbed_official | 125:23cc3068a9e4 | 12 | * and/or other materials provided with the distribution. |
mbed_official | 125:23cc3068a9e4 | 13 | * 3. Neither the name of STMicroelectronics nor the names of its contributors |
mbed_official | 125:23cc3068a9e4 | 14 | * may be used to endorse or promote products derived from this software |
mbed_official | 125:23cc3068a9e4 | 15 | * without specific prior written permission. |
mbed_official | 125:23cc3068a9e4 | 16 | * |
mbed_official | 125:23cc3068a9e4 | 17 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
mbed_official | 125:23cc3068a9e4 | 18 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
mbed_official | 125:23cc3068a9e4 | 19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
mbed_official | 125:23cc3068a9e4 | 20 | * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE |
mbed_official | 125:23cc3068a9e4 | 21 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
mbed_official | 125:23cc3068a9e4 | 22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
mbed_official | 125:23cc3068a9e4 | 23 | * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
mbed_official | 125:23cc3068a9e4 | 24 | * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
mbed_official | 125:23cc3068a9e4 | 25 | * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
mbed_official | 125:23cc3068a9e4 | 26 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
mbed_official | 125:23cc3068a9e4 | 27 | */ |
mbed_official | 125:23cc3068a9e4 | 28 | #include <stddef.h> |
mbed_official | 125:23cc3068a9e4 | 29 | #include "us_ticker_api.h" |
mbed_official | 125:23cc3068a9e4 | 30 | #include "PeripheralNames.h" |
mbed_official | 125:23cc3068a9e4 | 31 | |
mbed_official | 125:23cc3068a9e4 | 32 | // 32-bit timer selection |
mbed_official | 125:23cc3068a9e4 | 33 | #define TIM_MST TIM2 |
mbed_official | 125:23cc3068a9e4 | 34 | #define TIM_MST_IRQ TIM2_IRQn |
mbed_official | 125:23cc3068a9e4 | 35 | #define TIM_MST_RCC RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE) |
mbed_official | 125:23cc3068a9e4 | 36 | |
mbed_official | 125:23cc3068a9e4 | 37 | static int us_ticker_inited = 0; |
mbed_official | 125:23cc3068a9e4 | 38 | |
mbed_official | 125:23cc3068a9e4 | 39 | void us_ticker_init(void) { |
mbed_official | 125:23cc3068a9e4 | 40 | TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; |
mbed_official | 135:067cc8ba23da | 41 | |
mbed_official | 125:23cc3068a9e4 | 42 | if (us_ticker_inited) return; |
mbed_official | 125:23cc3068a9e4 | 43 | us_ticker_inited = 1; |
mbed_official | 135:067cc8ba23da | 44 | |
mbed_official | 125:23cc3068a9e4 | 45 | // Enable timer clock |
mbed_official | 125:23cc3068a9e4 | 46 | TIM_MST_RCC; |
mbed_official | 135:067cc8ba23da | 47 | |
mbed_official | 125:23cc3068a9e4 | 48 | // Configure time base |
mbed_official | 125:23cc3068a9e4 | 49 | TIM_TimeBaseStructInit(&TIM_TimeBaseStructure); |
mbed_official | 135:067cc8ba23da | 50 | TIM_TimeBaseStructure.TIM_Period = 0xFFFFFFFF; |
mbed_official | 304:89b9c3a9a045 | 51 | TIM_TimeBaseStructure.TIM_Prescaler = (uint16_t)(SystemCoreClock / 1000000) - 1; // 1 �s tick |
mbed_official | 125:23cc3068a9e4 | 52 | TIM_TimeBaseStructure.TIM_ClockDivision = 0; |
mbed_official | 135:067cc8ba23da | 53 | TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; |
mbed_official | 125:23cc3068a9e4 | 54 | TIM_TimeBaseInit(TIM_MST, &TIM_TimeBaseStructure); |
mbed_official | 135:067cc8ba23da | 55 | |
mbed_official | 125:23cc3068a9e4 | 56 | NVIC_SetVector(TIM_MST_IRQ, (uint32_t)us_ticker_irq_handler); |
mbed_official | 125:23cc3068a9e4 | 57 | NVIC_EnableIRQ(TIM_MST_IRQ); |
mbed_official | 135:067cc8ba23da | 58 | |
mbed_official | 125:23cc3068a9e4 | 59 | // Enable timer |
mbed_official | 125:23cc3068a9e4 | 60 | TIM_Cmd(TIM_MST, ENABLE); |
mbed_official | 125:23cc3068a9e4 | 61 | } |
mbed_official | 125:23cc3068a9e4 | 62 | |
mbed_official | 125:23cc3068a9e4 | 63 | uint32_t us_ticker_read() { |
mbed_official | 125:23cc3068a9e4 | 64 | if (!us_ticker_inited) us_ticker_init(); |
mbed_official | 125:23cc3068a9e4 | 65 | return TIM_MST->CNT; |
mbed_official | 125:23cc3068a9e4 | 66 | } |
mbed_official | 125:23cc3068a9e4 | 67 | |
mbed_official | 304:89b9c3a9a045 | 68 | void us_ticker_set_interrupt(timestamp_t timestamp) { |
mbed_official | 125:23cc3068a9e4 | 69 | // Set new output compare value |
mbed_official | 304:89b9c3a9a045 | 70 | TIM_SetCompare1(TIM_MST, (uint32_t)timestamp); |
mbed_official | 125:23cc3068a9e4 | 71 | // Enable IT |
mbed_official | 125:23cc3068a9e4 | 72 | TIM_ITConfig(TIM_MST, TIM_IT_CC1, ENABLE); |
mbed_official | 125:23cc3068a9e4 | 73 | } |
mbed_official | 125:23cc3068a9e4 | 74 | |
mbed_official | 125:23cc3068a9e4 | 75 | void us_ticker_disable_interrupt(void) { |
mbed_official | 125:23cc3068a9e4 | 76 | TIM_ITConfig(TIM_MST, TIM_IT_CC1, DISABLE); |
mbed_official | 125:23cc3068a9e4 | 77 | } |
mbed_official | 125:23cc3068a9e4 | 78 | |
mbed_official | 125:23cc3068a9e4 | 79 | void us_ticker_clear_interrupt(void) { |
mbed_official | 125:23cc3068a9e4 | 80 | TIM_ClearITPendingBit(TIM_MST, TIM_IT_CC1); |
mbed_official | 125:23cc3068a9e4 | 81 | } |