Ken Todotani / mbed-src

mbed library sources

Fork of mbed-src by mbed official

targets/hal/TARGET_STM/TARGET_NUCLEO_F401RE/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:
226:b062af740e40 
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?

UserRevisionLine numberNew contents of line
mbed_official 87:085cde657901 1 /* mbed Microcontroller Library
mbed_official 87:085cde657901 2 * Copyright (c) 2014, STMicroelectronics
mbed_official 87:085cde657901 3 * All rights reserved.
mbed_official 87:085cde657901 4 *
mbed_official 87:085cde657901 5 * Redistribution and use in source and binary forms, with or without
mbed_official 87:085cde657901 6 * modification, are permitted provided that the following conditions are met:
mbed_official 87:085cde657901 7 *
mbed_official 87:085cde657901 8 * 1. Redistributions of source code must retain the above copyright notice,
mbed_official 87:085cde657901 9 * this list of conditions and the following disclaimer.
mbed_official 87:085cde657901 10 * 2. Redistributions in binary form must reproduce the above copyright notice,
mbed_official 87:085cde657901 11 * this list of conditions and the following disclaimer in the documentation
mbed_official 87:085cde657901 12 * and/or other materials provided with the distribution.
mbed_official 87:085cde657901 13 * 3. Neither the name of STMicroelectronics nor the names of its contributors
mbed_official 87:085cde657901 14 * may be used to endorse or promote products derived from this software
mbed_official 87:085cde657901 15 * without specific prior written permission.
mbed_official 87:085cde657901 16 *
mbed_official 87:085cde657901 17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
mbed_official 87:085cde657901 18 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
mbed_official 87:085cde657901 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
mbed_official 87:085cde657901 20 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
mbed_official 87:085cde657901 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
mbed_official 87:085cde657901 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
mbed_official 87:085cde657901 23 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
mbed_official 87:085cde657901 24 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
mbed_official 87:085cde657901 25 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
mbed_official 87:085cde657901 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
mbed_official 87:085cde657901 27 */
mbed_official 87:085cde657901 28 #include <stddef.h>
mbed_official 87:085cde657901 29 #include "us_ticker_api.h"
mbed_official 87:085cde657901 30 #include "PeripheralNames.h"
mbed_official 87:085cde657901 31
mbed_official 226:b062af740e40 32 #define TIM_MST TIM5
mbed_official 87:085cde657901 33
mbed_official 87:085cde657901 34 static TIM_HandleTypeDef TimMasterHandle;
mbed_official 100:0412b5443284 35 static int us_ticker_inited = 0;
mbed_official 87:085cde657901 36
mbed_official 87:085cde657901 37 void us_ticker_init(void) {
mbed_official 87:085cde657901 38 if (us_ticker_inited) return;
mbed_official 87:085cde657901 39 us_ticker_inited = 1;
mbed_official 172:2f4f8c56b261 40
mbed_official 226:b062af740e40 41 TimMasterHandle.Instance = TIM_MST;
mbed_official 172:2f4f8c56b261 42
mbed_official 226:b062af740e40 43 HAL_InitTick(0); // The passed value is not used
mbed_official 87:085cde657901 44 }
mbed_official 87:085cde657901 45
mbed_official 87:085cde657901 46 uint32_t us_ticker_read() {
mbed_official 87:085cde657901 47 if (!us_ticker_inited) us_ticker_init();
mbed_official 100:0412b5443284 48 return TIM_MST->CNT;
mbed_official 87:085cde657901 49 }
mbed_official 87:085cde657901 50
mbed_official 304:89b9c3a9a045 51 void us_ticker_set_interrupt(timestamp_t timestamp) {
mbed_official 100:0412b5443284 52 // Set new output compare value
mbed_official 304:89b9c3a9a045 53 __HAL_TIM_SetCompare(&TimMasterHandle, TIM_CHANNEL_1, (uint32_t)timestamp);
mbed_official 100:0412b5443284 54 // Enable IT
mbed_official 100:0412b5443284 55 __HAL_TIM_ENABLE_IT(&TimMasterHandle, TIM_IT_CC1);
mbed_official 87:085cde657901 56 }
mbed_official 87:085cde657901 57
mbed_official 87:085cde657901 58 void us_ticker_disable_interrupt(void) {
mbed_official 87:085cde657901 59 __HAL_TIM_DISABLE_IT(&TimMasterHandle, TIM_IT_CC1);
mbed_official 87:085cde657901 60 }
mbed_official 87:085cde657901 61
mbed_official 87:085cde657901 62 void us_ticker_clear_interrupt(void) {
mbed_official 100:0412b5443284 63 __HAL_TIM_CLEAR_IT(&TimMasterHandle, TIM_IT_CC1);
mbed_official 87:085cde657901 64 }