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targets/TARGET_NORDIC/TARGET_NRF5/us_ticker.c@182:57724642e740, 2018-02-16 (annotated)

Committer:
AnnaBridge
Date:
Fri Feb 16 16:09:33 2018 +0000
Revision:
182:57724642e740
Parent:
175:b96e65c34a4d 
mbed-dev library. Release version 159.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
<> 149:156823d33999 1 /*
<> 149:156823d33999 2 * Copyright (c) 2013 Nordic Semiconductor ASA
<> 149:156823d33999 3 * All rights reserved.
<> 149:156823d33999 4 *
<> 149:156823d33999 5 * Redistribution and use in source and binary forms, with or without modification,
<> 149:156823d33999 6 * are permitted provided that the following conditions are met:
<> 149:156823d33999 7 *
<> 149:156823d33999 8 * 1. Redistributions of source code must retain the above copyright notice, this list
<> 149:156823d33999 9 * of conditions and the following disclaimer.
<> 149:156823d33999 10 *
<> 149:156823d33999 11 * 2. Redistributions in binary form, except as embedded into a Nordic Semiconductor ASA
<> 149:156823d33999 12 * integrated circuit in a product or a software update for such product, must reproduce
<> 149:156823d33999 13 * the above copyright notice, this list of conditions and the following disclaimer in
<> 149:156823d33999 14 * the documentation and/or other materials provided with the distribution.
<> 149:156823d33999 15 *
<> 149:156823d33999 16 * 3. Neither the name of Nordic Semiconductor ASA nor the names of its contributors may be
<> 149:156823d33999 17 * used to endorse or promote products derived from this software without specific prior
<> 149:156823d33999 18 * written permission.
<> 149:156823d33999 19 *
<> 149:156823d33999 20 * 4. This software, with or without modification, must only be used with a
<> 149:156823d33999 21 * Nordic Semiconductor ASA integrated circuit.
<> 149:156823d33999 22 *
<> 149:156823d33999 23 * 5. Any software provided in binary or object form under this license must not be reverse
<> 149:156823d33999 24 * engineered, decompiled, modified and/or disassembled.
<> 149:156823d33999 25 *
<> 149:156823d33999 26 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
<> 149:156823d33999 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
<> 149:156823d33999 28 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
<> 149:156823d33999 29 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
<> 149:156823d33999 30 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
<> 149:156823d33999 31 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
<> 149:156823d33999 32 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
<> 149:156823d33999 33 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
<> 149:156823d33999 34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
<> 149:156823d33999 35 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
<> 149:156823d33999 36 *
<> 149:156823d33999 37 */
<> 149:156823d33999 38
<> 149:156823d33999 39 #include "us_ticker_api.h"
<> 149:156823d33999 40 #include "common_rtc.h"
<> 149:156823d33999 41 #include "app_util.h"
<> 149:156823d33999 42 #include "nrf_drv_common.h"
<> 149:156823d33999 43 #include "lp_ticker_api.h"
Anna Bridge 163:74e0ce7f98e8 44 #include "mbed_critical.h"
<> 149:156823d33999 45
AnnaBridge 165:e614a9f1c9e2 46 #if defined(NRF52_ERRATA_20)
AnnaBridge 165:e614a9f1c9e2 47 #include "softdevice_handler.h"
AnnaBridge 165:e614a9f1c9e2 48 #endif
<> 149:156823d33999 49
<> 149:156823d33999 50 //------------------------------------------------------------------------------
<> 149:156823d33999 51 // Common stuff used also by lp_ticker and rtc_api (see "common_rtc.h").
<> 149:156823d33999 52 //
<> 149:156823d33999 53 #include "app_util_platform.h"
<> 149:156823d33999 54
<> 149:156823d33999 55 bool m_common_rtc_enabled = false;
<> 149:156823d33999 56 uint32_t volatile m_common_rtc_overflows = 0;
<> 149:156823d33999 57
Anna Bridge 163:74e0ce7f98e8 58 __STATIC_INLINE void rtc_ovf_event_check(void)
Anna Bridge 163:74e0ce7f98e8 59 {
Anna Bridge 163:74e0ce7f98e8 60 if (nrf_rtc_event_pending(COMMON_RTC_INSTANCE, NRF_RTC_EVENT_OVERFLOW)) {
Anna Bridge 163:74e0ce7f98e8 61 nrf_rtc_event_clear(COMMON_RTC_INSTANCE, NRF_RTC_EVENT_OVERFLOW);
Anna Bridge 163:74e0ce7f98e8 62 // Don't disable this event. It shall occur periodically.
Anna Bridge 163:74e0ce7f98e8 63
Anna Bridge 163:74e0ce7f98e8 64 ++m_common_rtc_overflows;
Anna Bridge 163:74e0ce7f98e8 65 }
Anna Bridge 163:74e0ce7f98e8 66 }
Anna Bridge 163:74e0ce7f98e8 67
<> 149:156823d33999 68 #if defined(TARGET_MCU_NRF51822)
<> 149:156823d33999 69 void common_rtc_irq_handler(void)
<> 149:156823d33999 70 #else
<> 149:156823d33999 71 void COMMON_RTC_IRQ_HANDLER(void)
<> 149:156823d33999 72 #endif
<> 149:156823d33999 73 {
Anna Bridge 163:74e0ce7f98e8 74
Anna Bridge 163:74e0ce7f98e8 75 rtc_ovf_event_check();
Anna Bridge 163:74e0ce7f98e8 76
<> 149:156823d33999 77 if (nrf_rtc_event_pending(COMMON_RTC_INSTANCE, US_TICKER_EVENT)) {
<> 149:156823d33999 78 us_ticker_irq_handler();
<> 149:156823d33999 79 }
<> 149:156823d33999 80
<> 149:156823d33999 81 #if DEVICE_LOWPOWERTIMER
<> 149:156823d33999 82 if (nrf_rtc_event_pending(COMMON_RTC_INSTANCE, LP_TICKER_EVENT)) {
<> 149:156823d33999 83
<> 149:156823d33999 84 lp_ticker_irq_handler();
<> 149:156823d33999 85 }
<> 149:156823d33999 86 #endif
AnnaBridge 165:e614a9f1c9e2 87 }
<> 149:156823d33999 88
AnnaBridge 165:e614a9f1c9e2 89 // Function for fix errata 20: RTC Register values are invalid
AnnaBridge 165:e614a9f1c9e2 90 __STATIC_INLINE void errata_20(void)
AnnaBridge 165:e614a9f1c9e2 91 {
AnnaBridge 165:e614a9f1c9e2 92 #if defined(NRF52_ERRATA_20)
AnnaBridge 165:e614a9f1c9e2 93 if (!softdevice_handler_is_enabled())
AnnaBridge 165:e614a9f1c9e2 94 {
AnnaBridge 165:e614a9f1c9e2 95 NRF_CLOCK->EVENTS_LFCLKSTARTED = 0;
AnnaBridge 165:e614a9f1c9e2 96 NRF_CLOCK->TASKS_LFCLKSTART = 1;
AnnaBridge 165:e614a9f1c9e2 97
AnnaBridge 165:e614a9f1c9e2 98 while (NRF_CLOCK->EVENTS_LFCLKSTARTED == 0)
AnnaBridge 165:e614a9f1c9e2 99 {
AnnaBridge 165:e614a9f1c9e2 100 }
AnnaBridge 165:e614a9f1c9e2 101 }
AnnaBridge 165:e614a9f1c9e2 102 NRF_RTC1->TASKS_STOP = 0;
AnnaBridge 165:e614a9f1c9e2 103 #endif
<> 149:156823d33999 104 }
<> 149:156823d33999 105
<> 150:02e0a0aed4ec 106 void RTC1_IRQHandler(void);
<> 150:02e0a0aed4ec 107
<> 149:156823d33999 108 void common_rtc_init(void)
<> 149:156823d33999 109 {
<> 149:156823d33999 110 if (m_common_rtc_enabled) {
<> 149:156823d33999 111 return;
<> 149:156823d33999 112 }
<> 149:156823d33999 113
AnnaBridge 165:e614a9f1c9e2 114 errata_20();
AnnaBridge 165:e614a9f1c9e2 115
<> 150:02e0a0aed4ec 116 NVIC_SetVector(RTC1_IRQn, (uint32_t)RTC1_IRQHandler);
<> 150:02e0a0aed4ec 117
<> 149:156823d33999 118 // RTC is driven by the low frequency (32.768 kHz) clock, a proper request
<> 149:156823d33999 119 // must be made to have it running.
<> 149:156823d33999 120 // Currently this clock is started in 'SystemInit' (see "system_nrf51.c"
<> 149:156823d33999 121 // or "system_nrf52.c", respectively).
<> 149:156823d33999 122
<> 149:156823d33999 123 nrf_rtc_prescaler_set(COMMON_RTC_INSTANCE, 0);
<> 149:156823d33999 124
<> 149:156823d33999 125 nrf_rtc_event_clear(COMMON_RTC_INSTANCE, US_TICKER_EVENT);
<> 149:156823d33999 126 #if defined(TARGET_MCU_NRF51822)
<> 149:156823d33999 127 nrf_rtc_event_clear(COMMON_RTC_INSTANCE, OS_TICK_EVENT);
<> 149:156823d33999 128 #endif
<> 149:156823d33999 129 #if DEVICE_LOWPOWERTIMER
<> 149:156823d33999 130 nrf_rtc_event_clear(COMMON_RTC_INSTANCE, LP_TICKER_EVENT);
<> 149:156823d33999 131 #endif
<> 149:156823d33999 132 nrf_rtc_event_clear(COMMON_RTC_INSTANCE, NRF_RTC_EVENT_OVERFLOW);
<> 149:156823d33999 133
<> 149:156823d33999 134 // Interrupts on all related events are enabled permanently. Particular
<> 149:156823d33999 135 // events will be enabled or disabled as needed (such approach is more
<> 149:156823d33999 136 // energy efficient).
<> 149:156823d33999 137 nrf_rtc_int_enable(COMMON_RTC_INSTANCE,
AnnaBridge 165:e614a9f1c9e2 138 #if DEVICE_LOWPOWERTIMER
<> 149:156823d33999 139 LP_TICKER_INT_MASK |
AnnaBridge 165:e614a9f1c9e2 140 #endif
<> 149:156823d33999 141 US_TICKER_INT_MASK |
<> 149:156823d33999 142 NRF_RTC_INT_OVERFLOW_MASK);
<> 149:156823d33999 143
<> 149:156823d33999 144 // This event is enabled permanently, since overflow indications are needed
<> 149:156823d33999 145 // continuously.
<> 149:156823d33999 146 nrf_rtc_event_enable(COMMON_RTC_INSTANCE, NRF_RTC_INT_OVERFLOW_MASK);
<> 149:156823d33999 147 // All other relevant events are initially disabled.
<> 149:156823d33999 148 nrf_rtc_event_disable(COMMON_RTC_INSTANCE,
AnnaBridge 165:e614a9f1c9e2 149 #if defined(TARGET_MCU_NRF51822)
<> 149:156823d33999 150 OS_TICK_INT_MASK |
AnnaBridge 165:e614a9f1c9e2 151 #endif
AnnaBridge 165:e614a9f1c9e2 152 #if DEVICE_LOWPOWERTIMER
<> 149:156823d33999 153 LP_TICKER_INT_MASK |
AnnaBridge 165:e614a9f1c9e2 154 #endif
<> 149:156823d33999 155 US_TICKER_INT_MASK);
<> 149:156823d33999 156
<> 149:156823d33999 157 nrf_drv_common_irq_enable(nrf_drv_get_IRQn(COMMON_RTC_INSTANCE),
<> 150:02e0a0aed4ec 158 #ifdef NRF51
<> 150:02e0a0aed4ec 159 APP_IRQ_PRIORITY_LOW
AnnaBridge 165:e614a9f1c9e2 160 #elif defined(NRF52) || defined(NRF52840_XXAA)
<> 150:02e0a0aed4ec 161 APP_IRQ_PRIORITY_LOWEST
<> 150:02e0a0aed4ec 162 #endif
<> 150:02e0a0aed4ec 163 );
<> 149:156823d33999 164
<> 149:156823d33999 165 nrf_rtc_task_trigger(COMMON_RTC_INSTANCE, NRF_RTC_TASK_START);
<> 149:156823d33999 166
<> 149:156823d33999 167 m_common_rtc_enabled = true;
<> 149:156823d33999 168 }
<> 149:156823d33999 169
Anna Bridge 163:74e0ce7f98e8 170 __STATIC_INLINE void rtc_ovf_event_safe_check(void)
Anna Bridge 163:74e0ce7f98e8 171 {
Anna Bridge 163:74e0ce7f98e8 172 core_util_critical_section_enter();
Anna Bridge 163:74e0ce7f98e8 173
Anna Bridge 163:74e0ce7f98e8 174 rtc_ovf_event_check();
Anna Bridge 163:74e0ce7f98e8 175
Anna Bridge 163:74e0ce7f98e8 176 core_util_critical_section_exit();
Anna Bridge 163:74e0ce7f98e8 177 }
Anna Bridge 163:74e0ce7f98e8 178
Anna Bridge 163:74e0ce7f98e8 179
<> 149:156823d33999 180 uint32_t common_rtc_32bit_ticks_get(void)
<> 149:156823d33999 181 {
Anna Bridge 163:74e0ce7f98e8 182 uint32_t ticks;
Anna Bridge 163:74e0ce7f98e8 183 uint32_t prev_overflows;
Anna Bridge 163:74e0ce7f98e8 184
Anna Bridge 163:74e0ce7f98e8 185 do {
Anna Bridge 163:74e0ce7f98e8 186 prev_overflows = m_common_rtc_overflows;
Anna Bridge 163:74e0ce7f98e8 187
Anna Bridge 163:74e0ce7f98e8 188 ticks = nrf_rtc_counter_get(COMMON_RTC_INSTANCE);
Anna Bridge 163:74e0ce7f98e8 189 // The counter used for time measurements is less than 32 bit wide,
Anna Bridge 163:74e0ce7f98e8 190 // so its value is complemented with the number of registered overflows
Anna Bridge 163:74e0ce7f98e8 191 // of the counter.
Anna Bridge 163:74e0ce7f98e8 192 ticks += (m_common_rtc_overflows << RTC_COUNTER_BITS);
Anna Bridge 163:74e0ce7f98e8 193
Anna Bridge 163:74e0ce7f98e8 194 // Check in case that OVF occurred during execution of a RTC handler (apply if call was from RTC handler)
Anna Bridge 163:74e0ce7f98e8 195 // m_common_rtc_overflows might been updated in this call.
Anna Bridge 163:74e0ce7f98e8 196 rtc_ovf_event_safe_check();
Anna Bridge 163:74e0ce7f98e8 197
Anna Bridge 163:74e0ce7f98e8 198 // If call was made from a low priority level m_common_rtc_overflows might have been updated in RTC handler.
Anna Bridge 163:74e0ce7f98e8 199 } while (m_common_rtc_overflows != prev_overflows);
Anna Bridge 163:74e0ce7f98e8 200
<> 149:156823d33999 201 return ticks;
<> 149:156823d33999 202 }
<> 149:156823d33999 203
<> 149:156823d33999 204 uint64_t common_rtc_64bit_us_get(void)
<> 149:156823d33999 205 {
<> 149:156823d33999 206 uint32_t ticks = common_rtc_32bit_ticks_get();
<> 149:156823d33999 207 // [ticks -> microseconds]
<> 149:156823d33999 208 return ROUNDED_DIV(((uint64_t)ticks) * 1000000, RTC_INPUT_FREQ);
<> 149:156823d33999 209 }
<> 149:156823d33999 210
<> 149:156823d33999 211 void common_rtc_set_interrupt(uint32_t us_timestamp, uint32_t cc_channel,
<> 149:156823d33999 212 uint32_t int_mask)
<> 149:156823d33999 213 {
<> 149:156823d33999 214 // The internal counter is clocked with a frequency that cannot be easily
<> 149:156823d33999 215 // multiplied to 1 MHz, therefore besides the translation of values
<> 149:156823d33999 216 // (microsecond <-> ticks) a special care of overflows handling must be
<> 149:156823d33999 217 // taken. Here the 32-bit timestamp value is complemented with information
<> 149:156823d33999 218 // about current the system up time of (ticks + number of overflows of tick
<> 149:156823d33999 219 // counter on upper bits, converted to microseconds), and such 64-bit value
<> 149:156823d33999 220 // is then translated to counter ticks. Finally, the lower 24 bits of thus
<> 149:156823d33999 221 // calculated value is written to the counter compare register to prepare
<> 149:156823d33999 222 // the interrupt generation.
<> 149:156823d33999 223 uint64_t current_time64 = common_rtc_64bit_us_get();
<> 149:156823d33999 224 // [add upper 32 bits from the current time to the timestamp value]
<> 149:156823d33999 225 uint64_t timestamp64 = us_timestamp +
<> 149:156823d33999 226 (current_time64 & ~(uint64_t)0xFFFFFFFF);
<> 149:156823d33999 227 // [if the original timestamp value happens to be after the 32 bit counter
<> 149:156823d33999 228 // of microsends overflows, correct the upper 32 bits accordingly]
<> 149:156823d33999 229 if (us_timestamp < (uint32_t)(current_time64 & 0xFFFFFFFF)) {
<> 149:156823d33999 230 timestamp64 += ((uint64_t)1 << 32);
<> 149:156823d33999 231 }
<> 149:156823d33999 232 // [microseconds -> ticks, always round the result up to avoid too early
<> 149:156823d33999 233 // interrupt generation]
<> 149:156823d33999 234 uint32_t compare_value =
<> 149:156823d33999 235 (uint32_t)CEIL_DIV((timestamp64) * RTC_INPUT_FREQ, 1000000);
<> 149:156823d33999 236
Anna Bridge 163:74e0ce7f98e8 237
Anna Bridge 163:74e0ce7f98e8 238 core_util_critical_section_enter();
<> 149:156823d33999 239 // The COMPARE event occurs when the value in compare register is N and
<> 149:156823d33999 240 // the counter value changes from N-1 to N. Therefore, the minimal safe
<> 149:156823d33999 241 // difference between the compare value to be set and the current counter
<> 149:156823d33999 242 // value is 2 ticks. This guarantees that the compare trigger is properly
<> 149:156823d33999 243 // setup before the compare condition occurs.
<> 149:156823d33999 244 uint32_t closest_safe_compare = common_rtc_32bit_ticks_get() + 2;
<> 149:156823d33999 245 if ((int)(compare_value - closest_safe_compare) <= 0) {
<> 149:156823d33999 246 compare_value = closest_safe_compare;
<> 149:156823d33999 247 }
<> 149:156823d33999 248
<> 149:156823d33999 249 nrf_rtc_cc_set(COMMON_RTC_INSTANCE, cc_channel, RTC_WRAP(compare_value));
<> 149:156823d33999 250 nrf_rtc_event_enable(COMMON_RTC_INSTANCE, int_mask);
Anna Bridge 163:74e0ce7f98e8 251
Anna Bridge 163:74e0ce7f98e8 252 core_util_critical_section_exit();
<> 149:156823d33999 253 }
<> 149:156823d33999 254 //------------------------------------------------------------------------------
<> 149:156823d33999 255
<> 149:156823d33999 256
<> 149:156823d33999 257 void us_ticker_init(void)
<> 149:156823d33999 258 {
<> 149:156823d33999 259 common_rtc_init();
<> 149:156823d33999 260 }
<> 149:156823d33999 261
<> 149:156823d33999 262 uint32_t us_ticker_read()
<> 149:156823d33999 263 {
<> 149:156823d33999 264 us_ticker_init();
<> 149:156823d33999 265 return (uint32_t)common_rtc_64bit_us_get();
<> 149:156823d33999 266 }
<> 149:156823d33999 267
<> 149:156823d33999 268 void us_ticker_set_interrupt(timestamp_t timestamp)
<> 149:156823d33999 269 {
<> 149:156823d33999 270 common_rtc_set_interrupt(timestamp,
<> 149:156823d33999 271 US_TICKER_CC_CHANNEL, US_TICKER_INT_MASK);
<> 149:156823d33999 272 }
<> 149:156823d33999 273
AnnaBridge 175:b96e65c34a4d 274 void us_ticker_fire_interrupt(void)
AnnaBridge 175:b96e65c34a4d 275 {
AnnaBridge 175:b96e65c34a4d 276 uint32_t closest_safe_compare = common_rtc_32bit_ticks_get() + 2;
AnnaBridge 175:b96e65c34a4d 277
AnnaBridge 175:b96e65c34a4d 278 nrf_rtc_cc_set(COMMON_RTC_INSTANCE, US_TICKER_CC_CHANNEL, RTC_WRAP(closest_safe_compare));
AnnaBridge 175:b96e65c34a4d 279 nrf_rtc_event_enable(COMMON_RTC_INSTANCE, US_TICKER_INT_MASK);
AnnaBridge 175:b96e65c34a4d 280 }
AnnaBridge 175:b96e65c34a4d 281
<> 149:156823d33999 282 void us_ticker_disable_interrupt(void)
<> 149:156823d33999 283 {
<> 149:156823d33999 284 nrf_rtc_event_disable(COMMON_RTC_INSTANCE, US_TICKER_INT_MASK);
<> 149:156823d33999 285 }
<> 149:156823d33999 286
<> 149:156823d33999 287 void us_ticker_clear_interrupt(void)
<> 149:156823d33999 288 {
<> 149:156823d33999 289 nrf_rtc_event_clear(COMMON_RTC_INSTANCE, US_TICKER_EVENT);
<> 149:156823d33999 290 }
<> 149:156823d33999 291
<> 149:156823d33999 292
<> 149:156823d33999 293 // Since there is no SysTick on NRF51, the RTC1 channel 1 is used as an
<> 149:156823d33999 294 // alternative source of RTOS ticks.
<> 149:156823d33999 295 #if defined(TARGET_MCU_NRF51822)
<> 149:156823d33999 296
<> 160:d5399cc887bb 297 #include "mbed_toolchain.h"
<> 149:156823d33999 298
<> 149:156823d33999 299
<> 149:156823d33999 300 #define MAX_RTC_COUNTER_VAL ((1uL << RTC_COUNTER_BITS) - 1)
<> 149:156823d33999 301
AnnaBridge 167:e84263d55307 302 #ifndef RTC1_CONFIG_FREQUENCY
AnnaBridge 167:e84263d55307 303 #define RTC1_CONFIG_FREQUENCY 32678 // [Hz]
AnnaBridge 167:e84263d55307 304 #endif
<> 149:156823d33999 305
AnnaBridge 167:e84263d55307 306
<> 149:156823d33999 307
AnnaBridge 167:e84263d55307 308 void COMMON_RTC_IRQ_HANDLER(void)
<> 149:156823d33999 309 {
AnnaBridge 175:b96e65c34a4d 310 if(!nrf_rtc_event_pending(COMMON_RTC_INSTANCE, OS_TICK_EVENT)) {
AnnaBridge 167:e84263d55307 311 common_rtc_irq_handler();
AnnaBridge 167:e84263d55307 312 }
<> 149:156823d33999 313 }
<> 149:156823d33999 314
AnnaBridge 175:b96e65c34a4d 315 IRQn_Type mbed_get_m0_tick_irqn()
AnnaBridge 165:e614a9f1c9e2 316 {
AnnaBridge 175:b96e65c34a4d 317 return SWI3_IRQn;
<> 149:156823d33999 318 }
<> 149:156823d33999 319
AnnaBridge 167:e84263d55307 320
<> 149:156823d33999 321 #endif // defined(TARGET_MCU_NRF51822)