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hal/LowPowerTickerWrapper.cpp@188:bcfe06ba3d64, 2018-11-08 (annotated)

Committer:
AnnaBridge
Date:
Thu Nov 08 11:46:34 2018 +0000
Revision:
188:bcfe06ba3d64
Child:
189:f392fc9709a3
mbed-dev library. Release version 164

Who changed what in which revision?

UserRevisionLine numberNew contents of line
AnnaBridge 188:bcfe06ba3d64 1 /* mbed Microcontroller Library
AnnaBridge 188:bcfe06ba3d64 2 * Copyright (c) 2018 ARM Limited
AnnaBridge 188:bcfe06ba3d64 3 *
AnnaBridge 188:bcfe06ba3d64 4 * Licensed under the Apache License, Version 2.0 (the "License");
AnnaBridge 188:bcfe06ba3d64 5 * you may not use this file except in compliance with the License.
AnnaBridge 188:bcfe06ba3d64 6 * You may obtain a copy of the License at
AnnaBridge 188:bcfe06ba3d64 7 *
AnnaBridge 188:bcfe06ba3d64 8 * http://www.apache.org/licenses/LICENSE-2.0
AnnaBridge 188:bcfe06ba3d64 9 *
AnnaBridge 188:bcfe06ba3d64 10 * Unless required by applicable law or agreed to in writing, software
AnnaBridge 188:bcfe06ba3d64 11 * distributed under the License is distributed on an "AS IS" BASIS,
AnnaBridge 188:bcfe06ba3d64 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
AnnaBridge 188:bcfe06ba3d64 13 * See the License for the specific language governing permissions and
AnnaBridge 188:bcfe06ba3d64 14 * limitations under the License.
AnnaBridge 188:bcfe06ba3d64 15 */
AnnaBridge 188:bcfe06ba3d64 16 #include "hal/LowPowerTickerWrapper.h"
AnnaBridge 188:bcfe06ba3d64 17 #include "platform/Callback.h"
AnnaBridge 188:bcfe06ba3d64 18
AnnaBridge 188:bcfe06ba3d64 19 LowPowerTickerWrapper::LowPowerTickerWrapper(const ticker_data_t *data, const ticker_interface_t *interface, uint32_t min_cycles_between_writes, uint32_t min_cycles_until_match)
AnnaBridge 188:bcfe06ba3d64 20 : _intf(data->interface), _min_count_between_writes(min_cycles_between_writes + 1), _min_count_until_match(min_cycles_until_match + 1), _suspended(false)
AnnaBridge 188:bcfe06ba3d64 21 {
AnnaBridge 188:bcfe06ba3d64 22 core_util_critical_section_enter();
AnnaBridge 188:bcfe06ba3d64 23
AnnaBridge 188:bcfe06ba3d64 24 this->data.interface = interface;
AnnaBridge 188:bcfe06ba3d64 25 this->data.queue = data->queue;
AnnaBridge 188:bcfe06ba3d64 26 _reset();
AnnaBridge 188:bcfe06ba3d64 27
AnnaBridge 188:bcfe06ba3d64 28 core_util_critical_section_exit();
AnnaBridge 188:bcfe06ba3d64 29 }
AnnaBridge 188:bcfe06ba3d64 30
AnnaBridge 188:bcfe06ba3d64 31 void LowPowerTickerWrapper::irq_handler(ticker_irq_handler_type handler)
AnnaBridge 188:bcfe06ba3d64 32 {
AnnaBridge 188:bcfe06ba3d64 33 core_util_critical_section_enter();
AnnaBridge 188:bcfe06ba3d64 34
AnnaBridge 188:bcfe06ba3d64 35 if (_pending_fire_now || _match_check(_intf->read()) || _suspended) {
AnnaBridge 188:bcfe06ba3d64 36 _timeout.detach();
AnnaBridge 188:bcfe06ba3d64 37 _pending_timeout = false;
AnnaBridge 188:bcfe06ba3d64 38 _pending_match = false;
AnnaBridge 188:bcfe06ba3d64 39 _pending_fire_now = false;
AnnaBridge 188:bcfe06ba3d64 40 if (handler) {
AnnaBridge 188:bcfe06ba3d64 41 handler(&data);
AnnaBridge 188:bcfe06ba3d64 42 }
AnnaBridge 188:bcfe06ba3d64 43 } else {
AnnaBridge 188:bcfe06ba3d64 44 // Spurious interrupt
AnnaBridge 188:bcfe06ba3d64 45 _intf->clear_interrupt();
AnnaBridge 188:bcfe06ba3d64 46 }
AnnaBridge 188:bcfe06ba3d64 47
AnnaBridge 188:bcfe06ba3d64 48 core_util_critical_section_exit();
AnnaBridge 188:bcfe06ba3d64 49 }
AnnaBridge 188:bcfe06ba3d64 50
AnnaBridge 188:bcfe06ba3d64 51 void LowPowerTickerWrapper::suspend()
AnnaBridge 188:bcfe06ba3d64 52 {
AnnaBridge 188:bcfe06ba3d64 53 core_util_critical_section_enter();
AnnaBridge 188:bcfe06ba3d64 54
AnnaBridge 188:bcfe06ba3d64 55 // Wait until rescheduling is allowed
AnnaBridge 188:bcfe06ba3d64 56 while (!_set_interrupt_allowed) {
AnnaBridge 188:bcfe06ba3d64 57 timestamp_t current = _intf->read();
AnnaBridge 188:bcfe06ba3d64 58 if (((current - _last_actual_set_interrupt) & _mask) >= _min_count_between_writes) {
AnnaBridge 188:bcfe06ba3d64 59 _set_interrupt_allowed = true;
AnnaBridge 188:bcfe06ba3d64 60 }
AnnaBridge 188:bcfe06ba3d64 61 }
AnnaBridge 188:bcfe06ba3d64 62
AnnaBridge 188:bcfe06ba3d64 63 _reset();
AnnaBridge 188:bcfe06ba3d64 64 _suspended = true;
AnnaBridge 188:bcfe06ba3d64 65
AnnaBridge 188:bcfe06ba3d64 66 core_util_critical_section_exit();
AnnaBridge 188:bcfe06ba3d64 67 }
AnnaBridge 188:bcfe06ba3d64 68
AnnaBridge 188:bcfe06ba3d64 69 void LowPowerTickerWrapper::resume()
AnnaBridge 188:bcfe06ba3d64 70 {
AnnaBridge 188:bcfe06ba3d64 71 core_util_critical_section_enter();
AnnaBridge 188:bcfe06ba3d64 72
AnnaBridge 188:bcfe06ba3d64 73 // Wait until rescheduling is allowed
AnnaBridge 188:bcfe06ba3d64 74 while (!_set_interrupt_allowed) {
AnnaBridge 188:bcfe06ba3d64 75 timestamp_t current = _intf->read();
AnnaBridge 188:bcfe06ba3d64 76 if (((current - _last_actual_set_interrupt) & _mask) >= _min_count_between_writes) {
AnnaBridge 188:bcfe06ba3d64 77 _set_interrupt_allowed = true;
AnnaBridge 188:bcfe06ba3d64 78 }
AnnaBridge 188:bcfe06ba3d64 79 }
AnnaBridge 188:bcfe06ba3d64 80
AnnaBridge 188:bcfe06ba3d64 81 _suspended = false;
AnnaBridge 188:bcfe06ba3d64 82
AnnaBridge 188:bcfe06ba3d64 83 core_util_critical_section_exit();
AnnaBridge 188:bcfe06ba3d64 84 }
AnnaBridge 188:bcfe06ba3d64 85
AnnaBridge 188:bcfe06ba3d64 86 bool LowPowerTickerWrapper::timeout_pending()
AnnaBridge 188:bcfe06ba3d64 87 {
AnnaBridge 188:bcfe06ba3d64 88 core_util_critical_section_enter();
AnnaBridge 188:bcfe06ba3d64 89
AnnaBridge 188:bcfe06ba3d64 90 bool pending = _pending_timeout;
AnnaBridge 188:bcfe06ba3d64 91
AnnaBridge 188:bcfe06ba3d64 92 core_util_critical_section_exit();
AnnaBridge 188:bcfe06ba3d64 93 return pending;
AnnaBridge 188:bcfe06ba3d64 94 }
AnnaBridge 188:bcfe06ba3d64 95
AnnaBridge 188:bcfe06ba3d64 96 void LowPowerTickerWrapper::init()
AnnaBridge 188:bcfe06ba3d64 97 {
AnnaBridge 188:bcfe06ba3d64 98 core_util_critical_section_enter();
AnnaBridge 188:bcfe06ba3d64 99
AnnaBridge 188:bcfe06ba3d64 100 _reset();
AnnaBridge 188:bcfe06ba3d64 101 _intf->init();
AnnaBridge 188:bcfe06ba3d64 102
AnnaBridge 188:bcfe06ba3d64 103 core_util_critical_section_exit();
AnnaBridge 188:bcfe06ba3d64 104 }
AnnaBridge 188:bcfe06ba3d64 105
AnnaBridge 188:bcfe06ba3d64 106 void LowPowerTickerWrapper::free()
AnnaBridge 188:bcfe06ba3d64 107 {
AnnaBridge 188:bcfe06ba3d64 108 core_util_critical_section_enter();
AnnaBridge 188:bcfe06ba3d64 109
AnnaBridge 188:bcfe06ba3d64 110 _reset();
AnnaBridge 188:bcfe06ba3d64 111 _intf->free();
AnnaBridge 188:bcfe06ba3d64 112
AnnaBridge 188:bcfe06ba3d64 113 core_util_critical_section_exit();
AnnaBridge 188:bcfe06ba3d64 114 }
AnnaBridge 188:bcfe06ba3d64 115
AnnaBridge 188:bcfe06ba3d64 116 uint32_t LowPowerTickerWrapper::read()
AnnaBridge 188:bcfe06ba3d64 117 {
AnnaBridge 188:bcfe06ba3d64 118 core_util_critical_section_enter();
AnnaBridge 188:bcfe06ba3d64 119
AnnaBridge 188:bcfe06ba3d64 120 timestamp_t current = _intf->read();
AnnaBridge 188:bcfe06ba3d64 121 if (!_suspended && _match_check(current)) {
AnnaBridge 188:bcfe06ba3d64 122 _intf->fire_interrupt();
AnnaBridge 188:bcfe06ba3d64 123 }
AnnaBridge 188:bcfe06ba3d64 124
AnnaBridge 188:bcfe06ba3d64 125 core_util_critical_section_exit();
AnnaBridge 188:bcfe06ba3d64 126 return current;
AnnaBridge 188:bcfe06ba3d64 127 }
AnnaBridge 188:bcfe06ba3d64 128
AnnaBridge 188:bcfe06ba3d64 129 void LowPowerTickerWrapper::set_interrupt(timestamp_t timestamp)
AnnaBridge 188:bcfe06ba3d64 130 {
AnnaBridge 188:bcfe06ba3d64 131 core_util_critical_section_enter();
AnnaBridge 188:bcfe06ba3d64 132
AnnaBridge 188:bcfe06ba3d64 133 _last_set_interrupt = _intf->read();
AnnaBridge 188:bcfe06ba3d64 134 _cur_match_time = timestamp;
AnnaBridge 188:bcfe06ba3d64 135 _pending_match = true;
AnnaBridge 188:bcfe06ba3d64 136 if (!_suspended) {
AnnaBridge 188:bcfe06ba3d64 137 _schedule_match(_last_set_interrupt);
AnnaBridge 188:bcfe06ba3d64 138 } else {
AnnaBridge 188:bcfe06ba3d64 139 _intf->set_interrupt(timestamp);
AnnaBridge 188:bcfe06ba3d64 140 _last_actual_set_interrupt = _last_set_interrupt;
AnnaBridge 188:bcfe06ba3d64 141 _set_interrupt_allowed = false;
AnnaBridge 188:bcfe06ba3d64 142 }
AnnaBridge 188:bcfe06ba3d64 143
AnnaBridge 188:bcfe06ba3d64 144 core_util_critical_section_exit();
AnnaBridge 188:bcfe06ba3d64 145 }
AnnaBridge 188:bcfe06ba3d64 146
AnnaBridge 188:bcfe06ba3d64 147 void LowPowerTickerWrapper::disable_interrupt()
AnnaBridge 188:bcfe06ba3d64 148 {
AnnaBridge 188:bcfe06ba3d64 149 core_util_critical_section_enter();
AnnaBridge 188:bcfe06ba3d64 150
AnnaBridge 188:bcfe06ba3d64 151 _intf->disable_interrupt();
AnnaBridge 188:bcfe06ba3d64 152
AnnaBridge 188:bcfe06ba3d64 153 core_util_critical_section_exit();
AnnaBridge 188:bcfe06ba3d64 154 }
AnnaBridge 188:bcfe06ba3d64 155
AnnaBridge 188:bcfe06ba3d64 156 void LowPowerTickerWrapper::clear_interrupt()
AnnaBridge 188:bcfe06ba3d64 157 {
AnnaBridge 188:bcfe06ba3d64 158 core_util_critical_section_enter();
AnnaBridge 188:bcfe06ba3d64 159
AnnaBridge 188:bcfe06ba3d64 160 _intf->clear_interrupt();
AnnaBridge 188:bcfe06ba3d64 161
AnnaBridge 188:bcfe06ba3d64 162 core_util_critical_section_exit();
AnnaBridge 188:bcfe06ba3d64 163 }
AnnaBridge 188:bcfe06ba3d64 164
AnnaBridge 188:bcfe06ba3d64 165 void LowPowerTickerWrapper::fire_interrupt()
AnnaBridge 188:bcfe06ba3d64 166 {
AnnaBridge 188:bcfe06ba3d64 167 core_util_critical_section_enter();
AnnaBridge 188:bcfe06ba3d64 168
AnnaBridge 188:bcfe06ba3d64 169 _pending_fire_now = 1;
AnnaBridge 188:bcfe06ba3d64 170 _intf->fire_interrupt();
AnnaBridge 188:bcfe06ba3d64 171
AnnaBridge 188:bcfe06ba3d64 172 core_util_critical_section_exit();
AnnaBridge 188:bcfe06ba3d64 173 }
AnnaBridge 188:bcfe06ba3d64 174
AnnaBridge 188:bcfe06ba3d64 175 const ticker_info_t *LowPowerTickerWrapper::get_info()
AnnaBridge 188:bcfe06ba3d64 176 {
AnnaBridge 188:bcfe06ba3d64 177
AnnaBridge 188:bcfe06ba3d64 178 core_util_critical_section_enter();
AnnaBridge 188:bcfe06ba3d64 179
AnnaBridge 188:bcfe06ba3d64 180 const ticker_info_t *info = _intf->get_info();
AnnaBridge 188:bcfe06ba3d64 181
AnnaBridge 188:bcfe06ba3d64 182 core_util_critical_section_exit();
AnnaBridge 188:bcfe06ba3d64 183 return info;
AnnaBridge 188:bcfe06ba3d64 184 }
AnnaBridge 188:bcfe06ba3d64 185
AnnaBridge 188:bcfe06ba3d64 186 void LowPowerTickerWrapper::_reset()
AnnaBridge 188:bcfe06ba3d64 187 {
AnnaBridge 188:bcfe06ba3d64 188 MBED_ASSERT(core_util_in_critical_section());
AnnaBridge 188:bcfe06ba3d64 189
AnnaBridge 188:bcfe06ba3d64 190 _timeout.detach();
AnnaBridge 188:bcfe06ba3d64 191 _pending_timeout = false;
AnnaBridge 188:bcfe06ba3d64 192 _pending_match = false;
AnnaBridge 188:bcfe06ba3d64 193 _pending_fire_now = false;
AnnaBridge 188:bcfe06ba3d64 194 _set_interrupt_allowed = true;
AnnaBridge 188:bcfe06ba3d64 195 _cur_match_time = 0;
AnnaBridge 188:bcfe06ba3d64 196 _last_set_interrupt = 0;
AnnaBridge 188:bcfe06ba3d64 197 _last_actual_set_interrupt = 0;
AnnaBridge 188:bcfe06ba3d64 198
AnnaBridge 188:bcfe06ba3d64 199 const ticker_info_t *info = _intf->get_info();
AnnaBridge 188:bcfe06ba3d64 200 if (info->bits >= 32) {
AnnaBridge 188:bcfe06ba3d64 201 _mask = 0xffffffff;
AnnaBridge 188:bcfe06ba3d64 202 } else {
AnnaBridge 188:bcfe06ba3d64 203 _mask = ((uint64_t)1 << info->bits) - 1;
AnnaBridge 188:bcfe06ba3d64 204 }
AnnaBridge 188:bcfe06ba3d64 205
AnnaBridge 188:bcfe06ba3d64 206 // Round us_per_tick up
AnnaBridge 188:bcfe06ba3d64 207 _us_per_tick = (1000000 + info->frequency - 1) / info->frequency;
AnnaBridge 188:bcfe06ba3d64 208 }
AnnaBridge 188:bcfe06ba3d64 209
AnnaBridge 188:bcfe06ba3d64 210 void LowPowerTickerWrapper::_timeout_handler()
AnnaBridge 188:bcfe06ba3d64 211 {
AnnaBridge 188:bcfe06ba3d64 212 core_util_critical_section_enter();
AnnaBridge 188:bcfe06ba3d64 213 _pending_timeout = false;
AnnaBridge 188:bcfe06ba3d64 214
AnnaBridge 188:bcfe06ba3d64 215 timestamp_t current = _intf->read();
AnnaBridge 188:bcfe06ba3d64 216 /* Add extra check for '_last_set_interrupt == _cur_match_time'
AnnaBridge 188:bcfe06ba3d64 217 *
AnnaBridge 188:bcfe06ba3d64 218 * When '_last_set_interrupt == _cur_match_time', _ticker_match_interval_passed sees it as
AnnaBridge 188:bcfe06ba3d64 219 * one-round interval rather than just-pass, so add extra check for it. In rare cases, we
AnnaBridge 188:bcfe06ba3d64 220 * may trap in _timeout_handler/_schedule_match loop. This check can break it.
AnnaBridge 188:bcfe06ba3d64 221 */
AnnaBridge 188:bcfe06ba3d64 222 if ((_last_set_interrupt == _cur_match_time) ||
AnnaBridge 188:bcfe06ba3d64 223 _ticker_match_interval_passed(_last_set_interrupt, current, _cur_match_time)) {
AnnaBridge 188:bcfe06ba3d64 224 _intf->fire_interrupt();
AnnaBridge 188:bcfe06ba3d64 225 } else {
AnnaBridge 188:bcfe06ba3d64 226 _schedule_match(current);
AnnaBridge 188:bcfe06ba3d64 227 }
AnnaBridge 188:bcfe06ba3d64 228
AnnaBridge 188:bcfe06ba3d64 229 core_util_critical_section_exit();
AnnaBridge 188:bcfe06ba3d64 230 }
AnnaBridge 188:bcfe06ba3d64 231
AnnaBridge 188:bcfe06ba3d64 232 bool LowPowerTickerWrapper::_match_check(timestamp_t current)
AnnaBridge 188:bcfe06ba3d64 233 {
AnnaBridge 188:bcfe06ba3d64 234 MBED_ASSERT(core_util_in_critical_section());
AnnaBridge 188:bcfe06ba3d64 235
AnnaBridge 188:bcfe06ba3d64 236 if (!_pending_match) {
AnnaBridge 188:bcfe06ba3d64 237 return false;
AnnaBridge 188:bcfe06ba3d64 238 }
AnnaBridge 188:bcfe06ba3d64 239 /* Add extra check for '_last_set_interrupt == _cur_match_time' as above */
AnnaBridge 188:bcfe06ba3d64 240 return (_last_set_interrupt == _cur_match_time) ||
AnnaBridge 188:bcfe06ba3d64 241 _ticker_match_interval_passed(_last_set_interrupt, current, _cur_match_time);
AnnaBridge 188:bcfe06ba3d64 242 }
AnnaBridge 188:bcfe06ba3d64 243
AnnaBridge 188:bcfe06ba3d64 244 uint32_t LowPowerTickerWrapper::_lp_ticks_to_us(uint32_t ticks)
AnnaBridge 188:bcfe06ba3d64 245 {
AnnaBridge 188:bcfe06ba3d64 246 MBED_ASSERT(core_util_in_critical_section());
AnnaBridge 188:bcfe06ba3d64 247
AnnaBridge 188:bcfe06ba3d64 248 // Add 4 microseconds to round up the micro second ticker time (which has a frequency of at least 250KHz - 4us period)
AnnaBridge 188:bcfe06ba3d64 249 return _us_per_tick * ticks + 4;
AnnaBridge 188:bcfe06ba3d64 250 }
AnnaBridge 188:bcfe06ba3d64 251
AnnaBridge 188:bcfe06ba3d64 252 void LowPowerTickerWrapper::_schedule_match(timestamp_t current)
AnnaBridge 188:bcfe06ba3d64 253 {
AnnaBridge 188:bcfe06ba3d64 254 MBED_ASSERT(core_util_in_critical_section());
AnnaBridge 188:bcfe06ba3d64 255
AnnaBridge 188:bcfe06ba3d64 256 // Check if _intf->set_interrupt is allowed
AnnaBridge 188:bcfe06ba3d64 257 if (!_set_interrupt_allowed) {
AnnaBridge 188:bcfe06ba3d64 258 if (((current - _last_actual_set_interrupt) & _mask) >= _min_count_between_writes) {
AnnaBridge 188:bcfe06ba3d64 259 _set_interrupt_allowed = true;
AnnaBridge 188:bcfe06ba3d64 260 }
AnnaBridge 188:bcfe06ba3d64 261 }
AnnaBridge 188:bcfe06ba3d64 262
AnnaBridge 188:bcfe06ba3d64 263 uint32_t cycles_until_match = (_cur_match_time - current) & _mask;
AnnaBridge 188:bcfe06ba3d64 264 bool too_close = cycles_until_match < _min_count_until_match;
AnnaBridge 188:bcfe06ba3d64 265
AnnaBridge 188:bcfe06ba3d64 266 if (!_set_interrupt_allowed) {
AnnaBridge 188:bcfe06ba3d64 267
AnnaBridge 188:bcfe06ba3d64 268 // Can't use _intf->set_interrupt so use microsecond Timeout instead
AnnaBridge 188:bcfe06ba3d64 269
AnnaBridge 188:bcfe06ba3d64 270 // Speed optimization - if a timer has already been scheduled
AnnaBridge 188:bcfe06ba3d64 271 // then don't schedule it again.
AnnaBridge 188:bcfe06ba3d64 272 if (!_pending_timeout) {
AnnaBridge 188:bcfe06ba3d64 273 uint32_t ticks = cycles_until_match < _min_count_until_match ? cycles_until_match : _min_count_until_match;
AnnaBridge 188:bcfe06ba3d64 274 _timeout.attach_us(mbed::callback(this, &LowPowerTickerWrapper::_timeout_handler), _lp_ticks_to_us(ticks));
AnnaBridge 188:bcfe06ba3d64 275 _pending_timeout = true;
AnnaBridge 188:bcfe06ba3d64 276 }
AnnaBridge 188:bcfe06ba3d64 277 return;
AnnaBridge 188:bcfe06ba3d64 278 }
AnnaBridge 188:bcfe06ba3d64 279
AnnaBridge 188:bcfe06ba3d64 280 if (!too_close) {
AnnaBridge 188:bcfe06ba3d64 281
AnnaBridge 188:bcfe06ba3d64 282 // Schedule LP ticker
AnnaBridge 188:bcfe06ba3d64 283 _intf->set_interrupt(_cur_match_time);
AnnaBridge 188:bcfe06ba3d64 284 current = _intf->read();
AnnaBridge 188:bcfe06ba3d64 285 _last_actual_set_interrupt = current;
AnnaBridge 188:bcfe06ba3d64 286 _set_interrupt_allowed = false;
AnnaBridge 188:bcfe06ba3d64 287
AnnaBridge 188:bcfe06ba3d64 288 // Check for overflow
AnnaBridge 188:bcfe06ba3d64 289 uint32_t new_cycles_until_match = (_cur_match_time - current) & _mask;
AnnaBridge 188:bcfe06ba3d64 290 if (new_cycles_until_match > cycles_until_match) {
AnnaBridge 188:bcfe06ba3d64 291 // Overflow so fire now
AnnaBridge 188:bcfe06ba3d64 292 _intf->fire_interrupt();
AnnaBridge 188:bcfe06ba3d64 293 return;
AnnaBridge 188:bcfe06ba3d64 294 }
AnnaBridge 188:bcfe06ba3d64 295
AnnaBridge 188:bcfe06ba3d64 296 // Update variables with new time
AnnaBridge 188:bcfe06ba3d64 297 cycles_until_match = new_cycles_until_match;
AnnaBridge 188:bcfe06ba3d64 298 too_close = cycles_until_match < _min_count_until_match;
AnnaBridge 188:bcfe06ba3d64 299 }
AnnaBridge 188:bcfe06ba3d64 300
AnnaBridge 188:bcfe06ba3d64 301 if (too_close) {
AnnaBridge 188:bcfe06ba3d64 302
AnnaBridge 188:bcfe06ba3d64 303 // Low power ticker incremented to less than _min_count_until_match
AnnaBridge 188:bcfe06ba3d64 304 // so low power ticker may not fire. Use Timeout to ensure it does fire.
AnnaBridge 188:bcfe06ba3d64 305 uint32_t ticks = cycles_until_match < _min_count_until_match ? cycles_until_match : _min_count_until_match;
AnnaBridge 188:bcfe06ba3d64 306 _timeout.attach_us(mbed::callback(this, &LowPowerTickerWrapper::_timeout_handler), _lp_ticks_to_us(ticks));
AnnaBridge 188:bcfe06ba3d64 307 _pending_timeout = true;
AnnaBridge 188:bcfe06ba3d64 308 return;
AnnaBridge 188:bcfe06ba3d64 309 }
AnnaBridge 188:bcfe06ba3d64 310 }