david dicarlo / mbed-src-FLL48

mbed library sources: Modified to operate FRDM-KL25Z at 48MHz from internal 32kHz oscillator (nothing else changed).

Fork of mbed-src by mbed official

The only file that changed is: mbed-src-FLL48/targets/cmsis/TARGET_Freescale/TARGET_KL25Z/system_MKL25Z4.h

targets/hal/TARGET_STM/TARGET_STM32F4XX/us_ticker.c@20:4263a77256ae, 2013-09-10 (annotated)

Committer:
bogdanm
Date:
Tue Sep 10 15:14:19 2013 +0300
Revision:
20:4263a77256ae
Sync with git revision 171dda705c947bf910926a0b73d6a4797802554d

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bogdanm 20:4263a77256ae 1 /* mbed Microcontroller Library
bogdanm 20:4263a77256ae 2 * Copyright (c) 2006-2013 ARM Limited
bogdanm 20:4263a77256ae 3 *
bogdanm 20:4263a77256ae 4 * Licensed under the Apache License, Version 2.0 (the "License");
bogdanm 20:4263a77256ae 5 * you may not use this file except in compliance with the License.
bogdanm 20:4263a77256ae 6 * You may obtain a copy of the License at
bogdanm 20:4263a77256ae 7 *
bogdanm 20:4263a77256ae 8 * http://www.apache.org/licenses/LICENSE-2.0
bogdanm 20:4263a77256ae 9 *
bogdanm 20:4263a77256ae 10 * Unless required by applicable law or agreed to in writing, software
bogdanm 20:4263a77256ae 11 * distributed under the License is distributed on an "AS IS" BASIS,
bogdanm 20:4263a77256ae 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
bogdanm 20:4263a77256ae 13 * See the License for the specific language governing permissions and
bogdanm 20:4263a77256ae 14 * limitations under the License.
bogdanm 20:4263a77256ae 15 */
bogdanm 20:4263a77256ae 16 #include <stddef.h>
bogdanm 20:4263a77256ae 17 #include "us_ticker_api.h"
bogdanm 20:4263a77256ae 18 #include "PeripheralNames.h"
bogdanm 20:4263a77256ae 19
bogdanm 20:4263a77256ae 20 #define US_TICKER_TIMER TIM2
bogdanm 20:4263a77256ae 21 #define US_TICKER_TIMER_IRQn TIM2_IRQn
bogdanm 20:4263a77256ae 22
bogdanm 20:4263a77256ae 23 int us_ticker_inited = 0;
bogdanm 20:4263a77256ae 24
bogdanm 20:4263a77256ae 25 void us_ticker_init(void) {
bogdanm 20:4263a77256ae 26 if (us_ticker_inited) return;
bogdanm 20:4263a77256ae 27 us_ticker_inited = 1;
bogdanm 20:4263a77256ae 28
bogdanm 20:4263a77256ae 29 RCC->APB1ENR |= RCC_APB1ENR_TIM2EN;
bogdanm 20:4263a77256ae 30
bogdanm 20:4263a77256ae 31 uint32_t PCLK = SystemCoreClock / 4;
bogdanm 20:4263a77256ae 32
bogdanm 20:4263a77256ae 33 uint32_t prescale = PCLK / 1000000; // default to 1MHz (1 us ticks)
bogdanm 20:4263a77256ae 34 US_TICKER_TIMER->PSC = prescale - 1;
bogdanm 20:4263a77256ae 35 US_TICKER_TIMER->CR1 |= TIM_CR1_CEN;
bogdanm 20:4263a77256ae 36 // Trigger an update - this needs to happen after the counter is enabled.
bogdanm 20:4263a77256ae 37 US_TICKER_TIMER->EGR |= TIM_EGR_UG;
bogdanm 20:4263a77256ae 38
bogdanm 20:4263a77256ae 39 NVIC_SetVector(US_TICKER_TIMER_IRQn, (uint32_t)us_ticker_irq_handler);
bogdanm 20:4263a77256ae 40 NVIC_EnableIRQ(US_TICKER_TIMER_IRQn);
bogdanm 20:4263a77256ae 41 }
bogdanm 20:4263a77256ae 42
bogdanm 20:4263a77256ae 43 uint32_t us_ticker_read() {
bogdanm 20:4263a77256ae 44 if (!us_ticker_inited)
bogdanm 20:4263a77256ae 45 us_ticker_init();
bogdanm 20:4263a77256ae 46
bogdanm 20:4263a77256ae 47 return US_TICKER_TIMER->CNT;
bogdanm 20:4263a77256ae 48 }
bogdanm 20:4263a77256ae 49
bogdanm 20:4263a77256ae 50 void us_ticker_set_interrupt(unsigned int timestamp) {
bogdanm 20:4263a77256ae 51 // set match value
bogdanm 20:4263a77256ae 52 US_TICKER_TIMER->CCR1 = timestamp;
bogdanm 20:4263a77256ae 53 // enable compare interrupt
bogdanm 20:4263a77256ae 54 US_TICKER_TIMER->DIER |= TIM_DIER_CC1IE;
bogdanm 20:4263a77256ae 55 }
bogdanm 20:4263a77256ae 56
bogdanm 20:4263a77256ae 57 void us_ticker_disable_interrupt(void) {
bogdanm 20:4263a77256ae 58 US_TICKER_TIMER->DIER &= ~TIM_DIER_CC1IE;
bogdanm 20:4263a77256ae 59 }
bogdanm 20:4263a77256ae 60
bogdanm 20:4263a77256ae 61 void us_ticker_clear_interrupt(void) {
bogdanm 20:4263a77256ae 62 US_TICKER_TIMER->SR &= ~TIM_SR_CC1IF;
bogdanm 20:4263a77256ae 63 }