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Superseded

This library was superseded by mbed-dev - https://os.mbed.com/users/mbed_official/code/mbed-dev/.

Development branch of the mbed library sources. This library is kept in synch with the latest changes from the mbed SDK and it is not guaranteed to work.

If you are looking for a stable and tested release, please import one of the official mbed library releases:

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The official Mbed 2 C/C++ SDK provides the software platform and libraries to build your applications.

Last commit 20 Feb 2019 by mbed official

targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/lp_ticker.c@525:c320967f86b9, 2015-04-28 (annotated)

Committer:
mbed_official
Date:
Tue Apr 28 11:45:12 2015 +0100
Revision:
525:c320967f86b9
Child:
548:1abac31e188e
Synchronized with git revision 299385b8331142b9dc524da7a986536f60b14553



Full URL: https://github.com/mbedmicro/mbed/commit/299385b8331142b9dc524da7a986536f60b14553/



Add in Silicon Labs targets with asynchronous API support

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 525:c320967f86b9 1 /* mbed Microcontroller Library
mbed_official 525:c320967f86b9 2 * Copyright (c) 2006-2013 ARM Limited
mbed_official 525:c320967f86b9 3 *
mbed_official 525:c320967f86b9 4 * Licensed under the Apache License, Version 2.0 (the "License");
mbed_official 525:c320967f86b9 5 * you may not use this file except in compliance with the License.
mbed_official 525:c320967f86b9 6 * You may obtain a copy of the License at
mbed_official 525:c320967f86b9 7 *
mbed_official 525:c320967f86b9 8 * http://www.apache.org/licenses/LICENSE-2.0
mbed_official 525:c320967f86b9 9 *
mbed_official 525:c320967f86b9 10 * Unless required by applicable law or agreed to in writing, software
mbed_official 525:c320967f86b9 11 * distributed under the License is distributed on an "AS IS" BASIS,
mbed_official 525:c320967f86b9 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbed_official 525:c320967f86b9 13 * See the License for the specific language governing permissions and
mbed_official 525:c320967f86b9 14 * limitations under the License.
mbed_official 525:c320967f86b9 15 */
mbed_official 525:c320967f86b9 16
mbed_official 525:c320967f86b9 17 #include "device.h"
mbed_official 525:c320967f86b9 18 #if DEVICE_LOWPOWERTIMER
mbed_official 525:c320967f86b9 19
mbed_official 525:c320967f86b9 20 #include "rtc_api.h"
mbed_official 525:c320967f86b9 21 #include "rtc_api_HAL.h"
mbed_official 525:c320967f86b9 22 #include "lp_ticker_api.h"
mbed_official 525:c320967f86b9 23
mbed_official 525:c320967f86b9 24 void lp_ticker_init()
mbed_official 525:c320967f86b9 25 {
mbed_official 525:c320967f86b9 26 rtc_init_real(RTC_INIT_LPTIMER);
mbed_official 525:c320967f86b9 27 rtc_set_comp0_handler((uint32_t)lp_ticker_irq_handler);
mbed_official 525:c320967f86b9 28 }
mbed_official 525:c320967f86b9 29
mbed_official 525:c320967f86b9 30 void lp_ticker_set_interrupt(timestamp_t timestamp) {
mbed_official 525:c320967f86b9 31 uint64_t timestamp_ticks;
mbed_official 525:c320967f86b9 32 uint64_t current_ticks = RTC_CounterGet();
mbed_official 525:c320967f86b9 33 timestamp_t current_time = ((uint64_t)(current_ticks * 1000000) / (LOW_ENERGY_CLOCK_FREQUENCY / RTC_CLOCKDIV_INT));
mbed_official 525:c320967f86b9 34
mbed_official 525:c320967f86b9 35
mbed_official 525:c320967f86b9 36 /* calculate offset value */
mbed_official 525:c320967f86b9 37 timestamp_t offset = timestamp - current_time;
mbed_official 525:c320967f86b9 38 if(offset > 0xEFFFFFFF) offset = 100;
mbed_official 525:c320967f86b9 39
mbed_official 525:c320967f86b9 40 /* map offset to RTC value */
mbed_official 525:c320967f86b9 41 // ticks = offset * RTC frequency div 1000000
mbed_official 525:c320967f86b9 42 timestamp_ticks = ((uint64_t)offset * (LOW_ENERGY_CLOCK_FREQUENCY / RTC_CLOCKDIV_INT)) / 1000000;
mbed_official 525:c320967f86b9 43 timestamp_ticks += current_ticks;
mbed_official 525:c320967f86b9 44
mbed_official 525:c320967f86b9 45 /* RTC has 24 bit resolution */
mbed_official 525:c320967f86b9 46 timestamp_ticks &= 0xFFFFFF;
mbed_official 525:c320967f86b9 47
mbed_official 525:c320967f86b9 48 /* check for RTC limitation */
mbed_official 525:c320967f86b9 49 if((timestamp_ticks - RTC_CounterGet()) >= 0x800000) timestamp_ticks = RTC_CounterGet() + 2;
mbed_official 525:c320967f86b9 50
mbed_official 525:c320967f86b9 51 /* Set callback */
mbed_official 525:c320967f86b9 52 RTC_FreezeEnable(true);
mbed_official 525:c320967f86b9 53 RTC_CompareSet(0, (uint32_t)timestamp_ticks);
mbed_official 525:c320967f86b9 54 RTC_IntEnable(RTC_IF_COMP0);
mbed_official 525:c320967f86b9 55 RTC_FreezeEnable(false);
mbed_official 525:c320967f86b9 56 }
mbed_official 525:c320967f86b9 57
mbed_official 525:c320967f86b9 58 inline void lp_ticker_disable_interrupt() {
mbed_official 525:c320967f86b9 59 RTC_IntDisable(RTC_IF_COMP0);
mbed_official 525:c320967f86b9 60 }
mbed_official 525:c320967f86b9 61
mbed_official 525:c320967f86b9 62 inline void lp_ticker_clear_interrupt() {
mbed_official 525:c320967f86b9 63 RTC_IntClear(RTC_IF_COMP0);
mbed_official 525:c320967f86b9 64 }
mbed_official 525:c320967f86b9 65
mbed_official 525:c320967f86b9 66 timestamp_t lp_ticker_read() {
mbed_official 525:c320967f86b9 67 uint64_t ticks_temp;
mbed_official 525:c320967f86b9 68 uint64_t ticks = RTC_CounterGet();
mbed_official 525:c320967f86b9 69
mbed_official 525:c320967f86b9 70 /* ticks = counter tick value
mbed_official 525:c320967f86b9 71 * timestamp = value in microseconds
mbed_official 525:c320967f86b9 72 * timestamp = ticks * 1.000.000 / RTC frequency
mbed_official 525:c320967f86b9 73 */
mbed_official 525:c320967f86b9 74
mbed_official 525:c320967f86b9 75 ticks_temp = (ticks * 1000000) / (LOW_ENERGY_CLOCK_FREQUENCY / RTC_CLOCKDIV_INT);
mbed_official 525:c320967f86b9 76 return (timestamp_t) (ticks_temp & 0xFFFFFFFF);
mbed_official 525:c320967f86b9 77 }
mbed_official 525:c320967f86b9 78
mbed_official 525:c320967f86b9 79 #endif