Bernhard Filzmaier / mbed-src

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Fork of mbed-src by mbed official

targets/hal/TARGET_STM/TARGET_NUCLEO_L152RE/us_ticker.c@76:aeb1df146756, 2014-01-27 (annotated)

Committer:
mbed_official
Date:
Mon Jan 27 14:30:07 2014 +0000
Revision:
76:aeb1df146756
Child:
84:f54042cbc282
Synchronized with git revision a31ec9c5f7bcb5c8a1b2eced103f6a1dfa921abd



Full URL: https://github.com/mbedmicro/mbed/commit/a31ec9c5f7bcb5c8a1b2eced103f6a1dfa921abd/



Add NUCLEO_L152RE

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 76:aeb1df146756 1 /* mbed Microcontroller Library
mbed_official 76:aeb1df146756 2 * Copyright (c) 2014, STMicroelectronics
mbed_official 76:aeb1df146756 3 * All rights reserved.
mbed_official 76:aeb1df146756 4 *
mbed_official 76:aeb1df146756 5 * Redistribution and use in source and binary forms, with or without
mbed_official 76:aeb1df146756 6 * modification, are permitted provided that the following conditions are met:
mbed_official 76:aeb1df146756 7 *
mbed_official 76:aeb1df146756 8 * 1. Redistributions of source code must retain the above copyright notice,
mbed_official 76:aeb1df146756 9 * this list of conditions and the following disclaimer.
mbed_official 76:aeb1df146756 10 * 2. Redistributions in binary form must reproduce the above copyright notice,
mbed_official 76:aeb1df146756 11 * this list of conditions and the following disclaimer in the documentation
mbed_official 76:aeb1df146756 12 * and/or other materials provided with the distribution.
mbed_official 76:aeb1df146756 13 * 3. Neither the name of STMicroelectronics nor the names of its contributors
mbed_official 76:aeb1df146756 14 * may be used to endorse or promote products derived from this software
mbed_official 76:aeb1df146756 15 * without specific prior written permission.
mbed_official 76:aeb1df146756 16 *
mbed_official 76:aeb1df146756 17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
mbed_official 76:aeb1df146756 18 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
mbed_official 76:aeb1df146756 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
mbed_official 76:aeb1df146756 20 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
mbed_official 76:aeb1df146756 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
mbed_official 76:aeb1df146756 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
mbed_official 76:aeb1df146756 23 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
mbed_official 76:aeb1df146756 24 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
mbed_official 76:aeb1df146756 25 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
mbed_official 76:aeb1df146756 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
mbed_official 76:aeb1df146756 27 */
mbed_official 76:aeb1df146756 28 #include <stddef.h>
mbed_official 76:aeb1df146756 29 #include "us_ticker_api.h"
mbed_official 76:aeb1df146756 30 #include "PeripheralNames.h"
mbed_official 76:aeb1df146756 31
mbed_official 76:aeb1df146756 32 // Timers selection:
mbed_official 76:aeb1df146756 33 // The Master timer clocks the Slave timer
mbed_official 76:aeb1df146756 34
mbed_official 76:aeb1df146756 35 #define TIM_MST TIM9
mbed_official 76:aeb1df146756 36 #define TIM_MST_IRQ TIM9_IRQn
mbed_official 76:aeb1df146756 37 #define TIM_MST_RCC RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM9, ENABLE)
mbed_official 76:aeb1df146756 38
mbed_official 76:aeb1df146756 39 #define TIM_SLV TIM4
mbed_official 76:aeb1df146756 40 #define TIM_SLV_IRQ TIM4_IRQn
mbed_official 76:aeb1df146756 41 #define TIM_SLV_RCC RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE)
mbed_official 76:aeb1df146756 42
mbed_official 76:aeb1df146756 43 #define MST_SLV_ITR TIM_TS_ITR3
mbed_official 76:aeb1df146756 44
mbed_official 76:aeb1df146756 45 int us_ticker_inited = 0;
mbed_official 76:aeb1df146756 46
mbed_official 76:aeb1df146756 47 void us_ticker_init(void) {
mbed_official 76:aeb1df146756 48
mbed_official 76:aeb1df146756 49 TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
mbed_official 76:aeb1df146756 50 TIM_OCInitTypeDef TIM_OCInitStructure;
mbed_official 76:aeb1df146756 51
mbed_official 76:aeb1df146756 52 if (us_ticker_inited) return;
mbed_official 76:aeb1df146756 53 us_ticker_inited = 1;
mbed_official 76:aeb1df146756 54
mbed_official 76:aeb1df146756 55 // Enable Timers clock
mbed_official 76:aeb1df146756 56 TIM_MST_RCC;
mbed_official 76:aeb1df146756 57 TIM_SLV_RCC;
mbed_official 76:aeb1df146756 58
mbed_official 76:aeb1df146756 59 // Master and Slave timers time base configuration
mbed_official 76:aeb1df146756 60 TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
mbed_official 76:aeb1df146756 61 TIM_TimeBaseStructure.TIM_Period = 0xFFFF;
mbed_official 76:aeb1df146756 62 TIM_TimeBaseStructure.TIM_Prescaler = (uint16_t)(SystemCoreClock / 1000000) - 1; // 1 µs tick
mbed_official 76:aeb1df146756 63 TIM_TimeBaseStructure.TIM_ClockDivision = 0;
mbed_official 76:aeb1df146756 64 TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
mbed_official 76:aeb1df146756 65 TIM_TimeBaseInit(TIM_MST, &TIM_TimeBaseStructure);
mbed_official 76:aeb1df146756 66 TIM_TimeBaseStructure.TIM_Prescaler = 0;
mbed_official 76:aeb1df146756 67 TIM_TimeBaseInit(TIM_SLV, &TIM_TimeBaseStructure);
mbed_official 76:aeb1df146756 68
mbed_official 76:aeb1df146756 69 // Master timer configuration
mbed_official 76:aeb1df146756 70 TIM_OCStructInit(&TIM_OCInitStructure);
mbed_official 76:aeb1df146756 71 TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle;
mbed_official 76:aeb1df146756 72 TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
mbed_official 76:aeb1df146756 73 TIM_OCInitStructure.TIM_Pulse = 0;
mbed_official 76:aeb1df146756 74 TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
mbed_official 76:aeb1df146756 75 TIM_OC1Init(TIM_MST, &TIM_OCInitStructure);
mbed_official 76:aeb1df146756 76 TIM_SelectMasterSlaveMode(TIM_MST, TIM_MasterSlaveMode_Enable);
mbed_official 76:aeb1df146756 77 TIM_SelectOutputTrigger(TIM_MST, TIM_TRGOSource_Update);
mbed_official 76:aeb1df146756 78
mbed_official 76:aeb1df146756 79 // Slave timer configuration
mbed_official 76:aeb1df146756 80 TIM_SelectSlaveMode(TIM_SLV, TIM_SlaveMode_External1);
mbed_official 76:aeb1df146756 81 // The connection between Master and Slave is done here
mbed_official 76:aeb1df146756 82 TIM_SelectInputTrigger(TIM_SLV, MST_SLV_ITR);
mbed_official 76:aeb1df146756 83
mbed_official 76:aeb1df146756 84 // Enable timers
mbed_official 76:aeb1df146756 85 TIM_Cmd(TIM_SLV, ENABLE);
mbed_official 76:aeb1df146756 86 TIM_Cmd(TIM_MST, ENABLE);
mbed_official 76:aeb1df146756 87 }
mbed_official 76:aeb1df146756 88
mbed_official 76:aeb1df146756 89 uint32_t us_ticker_read() {
mbed_official 76:aeb1df146756 90 uint32_t counter, counter2;
mbed_official 76:aeb1df146756 91 if (!us_ticker_inited) us_ticker_init();
mbed_official 76:aeb1df146756 92 // A situation might appear when Master overflows right after Slave is read and before the
mbed_official 76:aeb1df146756 93 // new (overflowed) value of Master is read. Which would make the code below consider the
mbed_official 76:aeb1df146756 94 // previous (incorrect) value of Slave and the new value of Master, which would return a
mbed_official 76:aeb1df146756 95 // value in the past. Avoid this by computing consecutive values of the timer until they
mbed_official 76:aeb1df146756 96 // are properly ordered.
mbed_official 76:aeb1df146756 97 counter = (uint32_t)((uint32_t)TIM_GetCounter(TIM_SLV) << 16);
mbed_official 76:aeb1df146756 98 counter += (uint32_t)TIM_GetCounter(TIM_MST);
mbed_official 76:aeb1df146756 99 while (1) {
mbed_official 76:aeb1df146756 100 counter2 = (uint32_t)((uint32_t)TIM_GetCounter(TIM_SLV) << 16);
mbed_official 76:aeb1df146756 101 counter2 += (uint32_t)TIM_GetCounter(TIM_MST);
mbed_official 76:aeb1df146756 102 if (counter2 > counter) {
mbed_official 76:aeb1df146756 103 break;
mbed_official 76:aeb1df146756 104 }
mbed_official 76:aeb1df146756 105 counter = counter2;
mbed_official 76:aeb1df146756 106 }
mbed_official 76:aeb1df146756 107 return counter2;
mbed_official 76:aeb1df146756 108 }
mbed_official 76:aeb1df146756 109
mbed_official 76:aeb1df146756 110 void us_ticker_set_interrupt(unsigned int timestamp) {
mbed_official 76:aeb1df146756 111 if (timestamp > 0xFFFF) {
mbed_official 76:aeb1df146756 112 TIM_SetCompare1(TIM_SLV, (uint16_t)((timestamp >> 16) & 0xFFFF));
mbed_official 76:aeb1df146756 113 TIM_ITConfig(TIM_SLV, TIM_IT_CC1, ENABLE);
mbed_official 76:aeb1df146756 114 NVIC_SetVector(TIM_SLV_IRQ, (uint32_t)us_ticker_irq_handler);
mbed_official 76:aeb1df146756 115 NVIC_EnableIRQ(TIM_SLV_IRQ);
mbed_official 76:aeb1df146756 116 }
mbed_official 76:aeb1df146756 117 else {
mbed_official 76:aeb1df146756 118 TIM_SetCompare1(TIM_MST, (uint16_t)timestamp);
mbed_official 76:aeb1df146756 119 TIM_ITConfig(TIM_MST, TIM_IT_CC1, ENABLE);
mbed_official 76:aeb1df146756 120 NVIC_SetVector(TIM_MST_IRQ, (uint32_t)us_ticker_irq_handler);
mbed_official 76:aeb1df146756 121 NVIC_EnableIRQ(TIM_MST_IRQ);
mbed_official 76:aeb1df146756 122 }
mbed_official 76:aeb1df146756 123 }
mbed_official 76:aeb1df146756 124
mbed_official 76:aeb1df146756 125 void us_ticker_disable_interrupt(void) {
mbed_official 76:aeb1df146756 126 TIM_ITConfig(TIM_MST, TIM_IT_CC1, DISABLE);
mbed_official 76:aeb1df146756 127 TIM_ITConfig(TIM_SLV, TIM_IT_CC1, DISABLE);
mbed_official 76:aeb1df146756 128 }
mbed_official 76:aeb1df146756 129
mbed_official 76:aeb1df146756 130 void us_ticker_clear_interrupt(void) {
mbed_official 76:aeb1df146756 131 TIM_ClearITPendingBit(TIM_MST, TIM_IT_CC1);
mbed_official 76:aeb1df146756 132 TIM_ClearITPendingBit(TIM_SLV, TIM_IT_CC1);
mbed_official 76:aeb1df146756 133 }