Ermanno Brusadin / mbed

mbed library sources

Dependents:   FRDM-KL46Z_LCD_Test FRDM-KL46Z_LCD_Test FRDM-KL46Z_Plantilla FRDM-KL46Z_Plantilla ... more

targets/hal/TARGET_STM/TARGET_STM32F4XX/us_ticker.c@0:6bc4ac881c8e, 2016-07-28 (annotated)

Committer:
ebrus
Date:
Thu Jul 28 15:56:34 2016 +0000
Revision:
0:6bc4ac881c8e
1;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
ebrus 0:6bc4ac881c8e 1 /* mbed Microcontroller Library
ebrus 0:6bc4ac881c8e 2 * Copyright (c) 2006-2013 ARM Limited
ebrus 0:6bc4ac881c8e 3 *
ebrus 0:6bc4ac881c8e 4 * Licensed under the Apache License, Version 2.0 (the "License");
ebrus 0:6bc4ac881c8e 5 * you may not use this file except in compliance with the License.
ebrus 0:6bc4ac881c8e 6 * You may obtain a copy of the License at
ebrus 0:6bc4ac881c8e 7 *
ebrus 0:6bc4ac881c8e 8 * http://www.apache.org/licenses/LICENSE-2.0
ebrus 0:6bc4ac881c8e 9 *
ebrus 0:6bc4ac881c8e 10 * Unless required by applicable law or agreed to in writing, software
ebrus 0:6bc4ac881c8e 11 * distributed under the License is distributed on an "AS IS" BASIS,
ebrus 0:6bc4ac881c8e 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
ebrus 0:6bc4ac881c8e 13 * See the License for the specific language governing permissions and
ebrus 0:6bc4ac881c8e 14 * limitations under the License.
ebrus 0:6bc4ac881c8e 15 */
ebrus 0:6bc4ac881c8e 16 #include <stddef.h>
ebrus 0:6bc4ac881c8e 17 #include "us_ticker_api.h"
ebrus 0:6bc4ac881c8e 18 #include "PeripheralNames.h"
ebrus 0:6bc4ac881c8e 19
ebrus 0:6bc4ac881c8e 20 #define US_TICKER_TIMER TIM2
ebrus 0:6bc4ac881c8e 21 #define US_TICKER_TIMER_IRQn TIM2_IRQn
ebrus 0:6bc4ac881c8e 22
ebrus 0:6bc4ac881c8e 23 int us_ticker_inited = 0;
ebrus 0:6bc4ac881c8e 24
ebrus 0:6bc4ac881c8e 25 void us_ticker_init(void) {
ebrus 0:6bc4ac881c8e 26 if (us_ticker_inited) return;
ebrus 0:6bc4ac881c8e 27 us_ticker_inited = 1;
ebrus 0:6bc4ac881c8e 28
ebrus 0:6bc4ac881c8e 29 RCC->APB1ENR |= RCC_APB1ENR_TIM2EN;
ebrus 0:6bc4ac881c8e 30
ebrus 0:6bc4ac881c8e 31 uint32_t PCLK = SystemCoreClock / 4;
ebrus 0:6bc4ac881c8e 32
ebrus 0:6bc4ac881c8e 33 uint32_t prescale = PCLK / 1000000; // default to 1MHz (1 us ticks)
ebrus 0:6bc4ac881c8e 34 US_TICKER_TIMER->PSC = prescale - 1;
ebrus 0:6bc4ac881c8e 35 US_TICKER_TIMER->CR1 |= TIM_CR1_CEN;
ebrus 0:6bc4ac881c8e 36 // Trigger an update - this needs to happen after the counter is enabled.
ebrus 0:6bc4ac881c8e 37 US_TICKER_TIMER->EGR |= TIM_EGR_UG;
ebrus 0:6bc4ac881c8e 38
ebrus 0:6bc4ac881c8e 39 NVIC_SetVector(US_TICKER_TIMER_IRQn, (uint32_t)us_ticker_irq_handler);
ebrus 0:6bc4ac881c8e 40 NVIC_EnableIRQ(US_TICKER_TIMER_IRQn);
ebrus 0:6bc4ac881c8e 41 }
ebrus 0:6bc4ac881c8e 42
ebrus 0:6bc4ac881c8e 43 uint32_t us_ticker_read() {
ebrus 0:6bc4ac881c8e 44 if (!us_ticker_inited)
ebrus 0:6bc4ac881c8e 45 us_ticker_init();
ebrus 0:6bc4ac881c8e 46
ebrus 0:6bc4ac881c8e 47 return US_TICKER_TIMER->CNT;
ebrus 0:6bc4ac881c8e 48 }
ebrus 0:6bc4ac881c8e 49
ebrus 0:6bc4ac881c8e 50 void us_ticker_set_interrupt(timestamp_t timestamp) {
ebrus 0:6bc4ac881c8e 51 // set match value
ebrus 0:6bc4ac881c8e 52 US_TICKER_TIMER->CCR1 = (uint32_t)timestamp;
ebrus 0:6bc4ac881c8e 53 // enable compare interrupt
ebrus 0:6bc4ac881c8e 54 US_TICKER_TIMER->DIER |= TIM_DIER_CC1IE;
ebrus 0:6bc4ac881c8e 55 }
ebrus 0:6bc4ac881c8e 56
ebrus 0:6bc4ac881c8e 57 void us_ticker_disable_interrupt(void) {
ebrus 0:6bc4ac881c8e 58 US_TICKER_TIMER->DIER &= ~TIM_DIER_CC1IE;
ebrus 0:6bc4ac881c8e 59 }
ebrus 0:6bc4ac881c8e 60
ebrus 0:6bc4ac881c8e 61 void us_ticker_clear_interrupt(void) {
ebrus 0:6bc4ac881c8e 62 US_TICKER_TIMER->SR &= ~TIM_SR_CC1IF;
ebrus 0:6bc4ac881c8e 63 }