mbed official / mbed-dev

mbed library sources. Supersedes mbed-src.

Dependents:   Nucleo_Hello_Encoder BLE_iBeaconScan AM1805_DEMO DISCO-F429ZI_ExportTemplate1 ... more

targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_NRF51/sleep.c@186:707f6e361f3e, 2018-06-22 (annotated)

Committer:
Anna Bridge
Date:
Fri Jun 22 16:45:37 2018 +0100
Revision:
186:707f6e361f3e
mbed-dev library. Release version 162

Who changed what in which revision?

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Anna Bridge 186:707f6e361f3e 1 /* mbed Microcontroller Library
Anna Bridge 186:707f6e361f3e 2 * Copyright (c) 2006-2013 ARM Limited
Anna Bridge 186:707f6e361f3e 3 *
Anna Bridge 186:707f6e361f3e 4 * Licensed under the Apache License, Version 2.0 (the "License");
Anna Bridge 186:707f6e361f3e 5 * you may not use this file except in compliance with the License.
Anna Bridge 186:707f6e361f3e 6 * You may obtain a copy of the License at
Anna Bridge 186:707f6e361f3e 7 *
Anna Bridge 186:707f6e361f3e 8 * http://www.apache.org/licenses/LICENSE-2.0
Anna Bridge 186:707f6e361f3e 9 *
Anna Bridge 186:707f6e361f3e 10 * Unless required by applicable law or agreed to in writing, software
Anna Bridge 186:707f6e361f3e 11 * distributed under the License is distributed on an "AS IS" BASIS,
Anna Bridge 186:707f6e361f3e 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
Anna Bridge 186:707f6e361f3e 13 * See the License for the specific language governing permissions and
Anna Bridge 186:707f6e361f3e 14 * limitations under the License.
Anna Bridge 186:707f6e361f3e 15 */
Anna Bridge 186:707f6e361f3e 16 #include "sleep_api.h"
Anna Bridge 186:707f6e361f3e 17 #include "cmsis.h"
Anna Bridge 186:707f6e361f3e 18 #include "mbed_interface.h"
Anna Bridge 186:707f6e361f3e 19 #include "softdevice_handler.h"
Anna Bridge 186:707f6e361f3e 20 #include "nrf_soc.h"
Anna Bridge 186:707f6e361f3e 21 #include "nrf_timer.h"
Anna Bridge 186:707f6e361f3e 22 #include "us_ticker.h"
Anna Bridge 186:707f6e361f3e 23
Anna Bridge 186:707f6e361f3e 24 // Mask of reserved bits of the register ICSR in the System Control Block peripheral
Anna Bridge 186:707f6e361f3e 25 // In this case, bits which are equal to 0 are the bits reserved in this register
Anna Bridge 186:707f6e361f3e 26 #define SCB_ICSR_RESERVED_BITS_MASK 0x9E43F03F
Anna Bridge 186:707f6e361f3e 27
Anna Bridge 186:707f6e361f3e 28 #define FPU_EXCEPTION_MASK 0x0000009F
Anna Bridge 186:707f6e361f3e 29
Anna Bridge 186:707f6e361f3e 30 extern bool us_ticker_initialized;
Anna Bridge 186:707f6e361f3e 31
Anna Bridge 186:707f6e361f3e 32 void hal_sleep(void)
Anna Bridge 186:707f6e361f3e 33 {
Anna Bridge 186:707f6e361f3e 34 // ensure debug is disconnected if semihost is enabled....
Anna Bridge 186:707f6e361f3e 35
Anna Bridge 186:707f6e361f3e 36 // Trigger an event when an interrupt is pending. This allows to wake up
Anna Bridge 186:707f6e361f3e 37 // the processor from disabled interrupts.
Anna Bridge 186:707f6e361f3e 38 SCB->SCR |= SCB_SCR_SEVONPEND_Msk;
Anna Bridge 186:707f6e361f3e 39
Anna Bridge 186:707f6e361f3e 40 #if defined(NRF52) || defined(NRF52840_XXAA)
Anna Bridge 186:707f6e361f3e 41 /* Clear exceptions and PendingIRQ from the FPU unit */
Anna Bridge 186:707f6e361f3e 42 __set_FPSCR(__get_FPSCR() & ~(FPU_EXCEPTION_MASK));
Anna Bridge 186:707f6e361f3e 43 (void) __get_FPSCR();
Anna Bridge 186:707f6e361f3e 44 NVIC_ClearPendingIRQ(FPU_IRQn);
Anna Bridge 186:707f6e361f3e 45 #endif
Anna Bridge 186:707f6e361f3e 46
Anna Bridge 186:707f6e361f3e 47 // If the SoftDevice is enabled, its API must be used to go to sleep.
Anna Bridge 186:707f6e361f3e 48 if (softdevice_handler_is_enabled()) {
Anna Bridge 186:707f6e361f3e 49 sd_power_mode_set(NRF_POWER_MODE_LOWPWR);
Anna Bridge 186:707f6e361f3e 50 sd_app_evt_wait();
Anna Bridge 186:707f6e361f3e 51 } else {
Anna Bridge 186:707f6e361f3e 52 NRF_POWER->TASKS_LOWPWR = 1;
Anna Bridge 186:707f6e361f3e 53
Anna Bridge 186:707f6e361f3e 54 // Note: it is not sufficient to just use WFE here, since the internal
Anna Bridge 186:707f6e361f3e 55 // event register may be already set from an event that occurred in the
Anna Bridge 186:707f6e361f3e 56 // past (like an SVC call to the SoftDevice) and in such case WFE will
Anna Bridge 186:707f6e361f3e 57 // just clear the register and continue execution.
Anna Bridge 186:707f6e361f3e 58 // Therefore, the strategy here is to first clear the event register
Anna Bridge 186:707f6e361f3e 59 // by using SEV/WFE pair, and then execute WFE again, unless there is
Anna Bridge 186:707f6e361f3e 60 // a pending interrupt.
Anna Bridge 186:707f6e361f3e 61
Anna Bridge 186:707f6e361f3e 62 // Set an event and wake up whatsoever, this will clear the event
Anna Bridge 186:707f6e361f3e 63 // register from all previous events set (SVC call included)
Anna Bridge 186:707f6e361f3e 64 __SEV();
Anna Bridge 186:707f6e361f3e 65 __WFE();
Anna Bridge 186:707f6e361f3e 66
Anna Bridge 186:707f6e361f3e 67 // Test if there is an interrupt pending (mask reserved regions)
Anna Bridge 186:707f6e361f3e 68 if (SCB->ICSR & (SCB_ICSR_RESERVED_BITS_MASK)) {
Anna Bridge 186:707f6e361f3e 69 // Ok, there is an interrut pending, no need to go to sleep
Anna Bridge 186:707f6e361f3e 70 return;
Anna Bridge 186:707f6e361f3e 71 } else {
Anna Bridge 186:707f6e361f3e 72 // next event will wakeup the CPU
Anna Bridge 186:707f6e361f3e 73 // If an interrupt occured between the test of SCB->ICSR and this
Anna Bridge 186:707f6e361f3e 74 // instruction, WFE will just not put the CPU to sleep
Anna Bridge 186:707f6e361f3e 75 __WFE();
Anna Bridge 186:707f6e361f3e 76 }
Anna Bridge 186:707f6e361f3e 77 }
Anna Bridge 186:707f6e361f3e 78 }
Anna Bridge 186:707f6e361f3e 79
Anna Bridge 186:707f6e361f3e 80 void hal_deepsleep(void)
Anna Bridge 186:707f6e361f3e 81 {
Anna Bridge 186:707f6e361f3e 82 if (us_ticker_initialized) {
Anna Bridge 186:707f6e361f3e 83 nrf_timer_task_trigger(NRF_TIMER1, NRF_TIMER_TASK_STOP);
Anna Bridge 186:707f6e361f3e 84 }
Anna Bridge 186:707f6e361f3e 85
Anna Bridge 186:707f6e361f3e 86 hal_sleep();
Anna Bridge 186:707f6e361f3e 87
Anna Bridge 186:707f6e361f3e 88 if (us_ticker_initialized) {
Anna Bridge 186:707f6e361f3e 89 nrf_timer_task_trigger(NRF_TIMER1, NRF_TIMER_TASK_START);
Anna Bridge 186:707f6e361f3e 90 }
Anna Bridge 186:707f6e361f3e 91
Anna Bridge 186:707f6e361f3e 92 // NRF_POWER->SYSTEMOFF=1;
Anna Bridge 186:707f6e361f3e 93 }