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targets/hal/TARGET_Maxim/TARGET_MAX32600/us_ticker.c@514:7668256dbe61, 2015-04-16 (annotated)

Committer:
mbed_official
Date:
Thu Apr 16 11:45:13 2015 +0100
Revision:
514:7668256dbe61
Child:
515:7467ef1f4ad8
Synchronized with git revision 29ab478a78892415a3c721cdc20b1755b7b01ba1



Full URL: https://github.com/mbedmicro/mbed/commit/29ab478a78892415a3c721cdc20b1755b7b01ba1/



LPC824, SSCI824 - Add GCC_ARM exporter support

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 514:7668256dbe61 1 /*******************************************************************************
mbed_official 514:7668256dbe61 2 * Copyright (C) 2015 Maxim Integrated Products, Inc., All Rights Reserved.
mbed_official 514:7668256dbe61 3 *
mbed_official 514:7668256dbe61 4 * Permission is hereby granted, free of charge, to any person obtaining a
mbed_official 514:7668256dbe61 5 * copy of this software and associated documentation files (the "Software"),
mbed_official 514:7668256dbe61 6 * to deal in the Software without restriction, including without limitation
mbed_official 514:7668256dbe61 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
mbed_official 514:7668256dbe61 8 * and/or sell copies of the Software, and to permit persons to whom the
mbed_official 514:7668256dbe61 9 * Software is furnished to do so, subject to the following conditions:
mbed_official 514:7668256dbe61 10 *
mbed_official 514:7668256dbe61 11 * The above copyright notice and this permission notice shall be included
mbed_official 514:7668256dbe61 12 * in all copies or substantial portions of the Software.
mbed_official 514:7668256dbe61 13 *
mbed_official 514:7668256dbe61 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
mbed_official 514:7668256dbe61 15 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
mbed_official 514:7668256dbe61 16 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
mbed_official 514:7668256dbe61 17 * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
mbed_official 514:7668256dbe61 18 * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
mbed_official 514:7668256dbe61 19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
mbed_official 514:7668256dbe61 20 * OTHER DEALINGS IN THE SOFTWARE.
mbed_official 514:7668256dbe61 21 *
mbed_official 514:7668256dbe61 22 * Except as contained in this notice, the name of Maxim Integrated
mbed_official 514:7668256dbe61 23 * Products, Inc. shall not be used except as stated in the Maxim Integrated
mbed_official 514:7668256dbe61 24 * Products, Inc. Branding Policy.
mbed_official 514:7668256dbe61 25 *
mbed_official 514:7668256dbe61 26 * The mere transfer of this software does not imply any licenses
mbed_official 514:7668256dbe61 27 * of trade secrets, proprietary technology, copyrights, patents,
mbed_official 514:7668256dbe61 28 * trademarks, maskwork rights, or any other form of intellectual
mbed_official 514:7668256dbe61 29 * property whatsoever. Maxim Integrated Products, Inc. retains all
mbed_official 514:7668256dbe61 30 * ownership rights.
mbed_official 514:7668256dbe61 31 *******************************************************************************
mbed_official 514:7668256dbe61 32 */
mbed_official 514:7668256dbe61 33
mbed_official 514:7668256dbe61 34 #include "mbed_error.h"
mbed_official 514:7668256dbe61 35 #include "us_ticker_api.h"
mbed_official 514:7668256dbe61 36 #include "PeripheralNames.h"
mbed_official 514:7668256dbe61 37 #include "tmr_regs.h"
mbed_official 514:7668256dbe61 38
mbed_official 514:7668256dbe61 39 #define US_TIMER MXC_TMR0
mbed_official 514:7668256dbe61 40 #define US_TIMER_IRQn TMR0_IRQn
mbed_official 514:7668256dbe61 41
mbed_official 514:7668256dbe61 42 static int us_ticker_inited = 0;
mbed_official 514:7668256dbe61 43 static uint32_t ticks_per_us;
mbed_official 514:7668256dbe61 44 static uint32_t tick_win;
mbed_official 514:7668256dbe61 45 static volatile uint64_t current_cnt; // Hold the current ticks
mbed_official 514:7668256dbe61 46 static volatile uint64_t event_cnt; // Holds the value of the next event
mbed_official 514:7668256dbe61 47
mbed_official 514:7668256dbe61 48 #define ticks_to_us(ticks) ((ticks) / ticks_per_us);
mbed_official 514:7668256dbe61 49 #define MAX_TICK_VAL ((uint64_t)0xFFFFFFFF * ticks_per_us)
mbed_official 514:7668256dbe61 50
mbed_official 514:7668256dbe61 51 //******************************************************************************
mbed_official 514:7668256dbe61 52 static inline void inc_current_cnt(uint32_t inc) {
mbed_official 514:7668256dbe61 53
mbed_official 514:7668256dbe61 54 // Overflow the ticker when the us ticker overflows
mbed_official 514:7668256dbe61 55 current_cnt += inc;
mbed_official 514:7668256dbe61 56 if(current_cnt > MAX_TICK_VAL) {
mbed_official 514:7668256dbe61 57 current_cnt -= (MAX_TICK_VAL + 1);
mbed_official 514:7668256dbe61 58 }
mbed_official 514:7668256dbe61 59 }
mbed_official 514:7668256dbe61 60
mbed_official 514:7668256dbe61 61 //******************************************************************************
mbed_official 514:7668256dbe61 62 static inline int event_passed(uint64_t current, uint64_t event) {
mbed_official 514:7668256dbe61 63
mbed_official 514:7668256dbe61 64 // Determine if the event has already happened.
mbed_official 514:7668256dbe61 65 // If the event is behind the current ticker, within a window,
mbed_official 514:7668256dbe61 66 // then the event has already happened.
mbed_official 514:7668256dbe61 67 if(((current < tick_win) && ((event < current) ||
mbed_official 514:7668256dbe61 68 (event > (MAX_TICK_VAL - (tick_win - current))))) ||
mbed_official 514:7668256dbe61 69 ((event < current) && (event > (current - tick_win)))) {
mbed_official 514:7668256dbe61 70 return 1;
mbed_official 514:7668256dbe61 71 }
mbed_official 514:7668256dbe61 72
mbed_official 514:7668256dbe61 73 return 0;
mbed_official 514:7668256dbe61 74 }
mbed_official 514:7668256dbe61 75
mbed_official 514:7668256dbe61 76 //******************************************************************************
mbed_official 514:7668256dbe61 77 static inline uint64_t event_diff(uint64_t current, uint64_t event) {
mbed_official 514:7668256dbe61 78
mbed_official 514:7668256dbe61 79 // Check to see if the ticker will overflow before the event
mbed_official 514:7668256dbe61 80 if(current <= event) {
mbed_official 514:7668256dbe61 81 return (event - current);
mbed_official 514:7668256dbe61 82 }
mbed_official 514:7668256dbe61 83
mbed_official 514:7668256dbe61 84 return ((MAX_TICK_VAL - current) + event);
mbed_official 514:7668256dbe61 85 }
mbed_official 514:7668256dbe61 86
mbed_official 514:7668256dbe61 87 //******************************************************************************
mbed_official 514:7668256dbe61 88 static void tmr_handler(void)
mbed_official 514:7668256dbe61 89 {
mbed_official 514:7668256dbe61 90 uint32_t term_cnt32 = US_TIMER->term_cnt32;
mbed_official 514:7668256dbe61 91 US_TIMER->term_cnt32 = 0xFFFFFFFF; // reset to max value to prevent further interrupts
mbed_official 514:7668256dbe61 92 US_TIMER->intfl = (MXC_F_TMR_INTFL_TIMER0 | MXC_F_TMR_INTFL_TIMER1); // clear interrupt
mbed_official 514:7668256dbe61 93 NVIC_ClearPendingIRQ(US_TIMER_IRQn);
mbed_official 514:7668256dbe61 94
mbed_official 514:7668256dbe61 95 inc_current_cnt(term_cnt32);
mbed_official 514:7668256dbe61 96
mbed_official 514:7668256dbe61 97 if (event_passed(current_cnt + US_TIMER->count32, event_cnt )) {
mbed_official 514:7668256dbe61 98 // the timestamp has expired
mbed_official 514:7668256dbe61 99 event_cnt = -1; // reset to max value
mbed_official 514:7668256dbe61 100 us_ticker_irq_handler();
mbed_official 514:7668256dbe61 101 } else {
mbed_official 514:7668256dbe61 102
mbed_official 514:7668256dbe61 103 uint64_t diff = event_diff(current_cnt, event_cnt);
mbed_official 514:7668256dbe61 104 if (diff < (uint64_t)0xFFFFFFFF) {
mbed_official 514:7668256dbe61 105 // the event occurs before the next overflow
mbed_official 514:7668256dbe61 106 US_TIMER->term_cnt32 = diff;
mbed_official 514:7668256dbe61 107
mbed_official 514:7668256dbe61 108 // Since the timer keeps counting after the terminal value is reached, it is possible that the new
mbed_official 514:7668256dbe61 109 // terminal value is in the past.
mbed_official 514:7668256dbe61 110 if (US_TIMER->term_cnt32 < US_TIMER->count32) {
mbed_official 514:7668256dbe61 111 // the timestamp has expired
mbed_official 514:7668256dbe61 112 US_TIMER->term_cnt32 = 0xFFFFFFFF; // reset to max value to prevent further interrupts
mbed_official 514:7668256dbe61 113 US_TIMER->intfl = (MXC_F_TMR_INTFL_TIMER0 | MXC_F_TMR_INTFL_TIMER1); // clear interrupt
mbed_official 514:7668256dbe61 114 NVIC_ClearPendingIRQ(US_TIMER_IRQn);
mbed_official 514:7668256dbe61 115 event_cnt = -1; // reset to max value
mbed_official 514:7668256dbe61 116 us_ticker_irq_handler();
mbed_official 514:7668256dbe61 117 }
mbed_official 514:7668256dbe61 118 }
mbed_official 514:7668256dbe61 119 }
mbed_official 514:7668256dbe61 120 }
mbed_official 514:7668256dbe61 121
mbed_official 514:7668256dbe61 122 //******************************************************************************
mbed_official 514:7668256dbe61 123 void us_ticker_init(void)
mbed_official 514:7668256dbe61 124 {
mbed_official 514:7668256dbe61 125 if (us_ticker_inited)
mbed_official 514:7668256dbe61 126 return;
mbed_official 514:7668256dbe61 127 us_ticker_inited = 1;
mbed_official 514:7668256dbe61 128
mbed_official 514:7668256dbe61 129 current_cnt = 0;
mbed_official 514:7668256dbe61 130 event_cnt = -1; // initialize to max value
mbed_official 514:7668256dbe61 131
mbed_official 514:7668256dbe61 132 if (SystemCoreClock <= 1000000) {
mbed_official 514:7668256dbe61 133 error("us_ticker cannot operate at this SystemCoreClock");
mbed_official 514:7668256dbe61 134 return;
mbed_official 514:7668256dbe61 135 }
mbed_official 514:7668256dbe61 136
mbed_official 514:7668256dbe61 137 // Configure timer for 32-bit continuous mode with /1 prescaler
mbed_official 514:7668256dbe61 138 US_TIMER->ctrl = MXC_E_TMR_MODE_CONTINUOUS << MXC_F_TMR_CTRL_MODE_POS | (0 << MXC_F_TMR_CTRL_PRESCALE_POS);
mbed_official 514:7668256dbe61 139 ticks_per_us = SystemCoreClock / 1000000;
mbed_official 514:7668256dbe61 140
mbed_official 514:7668256dbe61 141 // Set the tick window to 10ms
mbed_official 514:7668256dbe61 142 tick_win = SystemCoreClock/100;
mbed_official 514:7668256dbe61 143
mbed_official 514:7668256dbe61 144 // Set timer overflow to the max
mbed_official 514:7668256dbe61 145 US_TIMER->term_cnt32 = 0xFFFFFFFF;
mbed_official 514:7668256dbe61 146 US_TIMER->pwm_cap32 = 0xFFFFFFFF;
mbed_official 514:7668256dbe61 147 US_TIMER->count32 = 0;
mbed_official 514:7668256dbe61 148
mbed_official 514:7668256dbe61 149 US_TIMER->intfl = (MXC_F_TMR_INTFL_TIMER0 | MXC_F_TMR_INTFL_TIMER1); // clear pending interrupts
mbed_official 514:7668256dbe61 150
mbed_official 514:7668256dbe61 151 NVIC_SetVector(US_TIMER_IRQn, (uint32_t)tmr_handler);
mbed_official 514:7668256dbe61 152 NVIC_EnableIRQ(US_TIMER_IRQn);
mbed_official 514:7668256dbe61 153
mbed_official 514:7668256dbe61 154 US_TIMER->inten |= MXC_F_TMR_INTEN_TIMER0; // enable interrupts
mbed_official 514:7668256dbe61 155 US_TIMER->ctrl |= MXC_F_TMR_CTRL_ENABLE0; // enable timer
mbed_official 514:7668256dbe61 156 }
mbed_official 514:7668256dbe61 157
mbed_official 514:7668256dbe61 158 //******************************************************************************
mbed_official 514:7668256dbe61 159 void us_ticker_deinit(void)
mbed_official 514:7668256dbe61 160 {
mbed_official 514:7668256dbe61 161 US_TIMER->ctrl = 0; // disable timer
mbed_official 514:7668256dbe61 162 US_TIMER->inten = 0; // disable interrupts
mbed_official 514:7668256dbe61 163 US_TIMER->intfl = (MXC_F_TMR_INTFL_TIMER0 | MXC_F_TMR_INTFL_TIMER1); // clear interrupts
mbed_official 514:7668256dbe61 164 us_ticker_inited = 0;
mbed_official 514:7668256dbe61 165 }
mbed_official 514:7668256dbe61 166
mbed_official 514:7668256dbe61 167 //******************************************************************************
mbed_official 514:7668256dbe61 168 uint32_t us_ticker_read(void)
mbed_official 514:7668256dbe61 169 {
mbed_official 514:7668256dbe61 170 uint64_t current_cnt1, current_cnt2;
mbed_official 514:7668256dbe61 171 uint32_t term_cnt, tmr_cnt;
mbed_official 514:7668256dbe61 172 int intfl1, intfl2;
mbed_official 514:7668256dbe61 173
mbed_official 514:7668256dbe61 174 if (!us_ticker_inited)
mbed_official 514:7668256dbe61 175 us_ticker_init();
mbed_official 514:7668256dbe61 176
mbed_official 514:7668256dbe61 177 // Ensure coherency between current_cnt and US_TIMER->count32
mbed_official 514:7668256dbe61 178 do {
mbed_official 514:7668256dbe61 179 current_cnt1 = current_cnt;
mbed_official 514:7668256dbe61 180 intfl1 = US_TIMER->intfl;
mbed_official 514:7668256dbe61 181 term_cnt = US_TIMER->term_cnt32;
mbed_official 514:7668256dbe61 182 tmr_cnt = US_TIMER->count32;
mbed_official 514:7668256dbe61 183 intfl2 = US_TIMER->intfl;
mbed_official 514:7668256dbe61 184 current_cnt2 = current_cnt;
mbed_official 514:7668256dbe61 185 } while ((current_cnt1 != current_cnt2) || (intfl1 != intfl2));
mbed_official 514:7668256dbe61 186
mbed_official 514:7668256dbe61 187 if (intfl1) {
mbed_official 514:7668256dbe61 188 current_cnt1 += term_cnt;
mbed_official 514:7668256dbe61 189 }
mbed_official 514:7668256dbe61 190
mbed_official 514:7668256dbe61 191 current_cnt1 += tmr_cnt;
mbed_official 514:7668256dbe61 192
mbed_official 514:7668256dbe61 193 return (current_cnt1 / ticks_per_us);
mbed_official 514:7668256dbe61 194 }
mbed_official 514:7668256dbe61 195
mbed_official 514:7668256dbe61 196 //******************************************************************************
mbed_official 514:7668256dbe61 197 void us_ticker_set_interrupt(timestamp_t timestamp)
mbed_official 514:7668256dbe61 198 {
mbed_official 514:7668256dbe61 199 // Note: interrupts are disabled before this function is called.
mbed_official 514:7668256dbe61 200 US_TIMER->ctrl &= ~MXC_F_TMR_CTRL_ENABLE0; // disable timer
mbed_official 514:7668256dbe61 201
mbed_official 514:7668256dbe61 202 if (US_TIMER->intfl) {
mbed_official 514:7668256dbe61 203 US_TIMER->intfl = (MXC_F_TMR_INTFL_TIMER0 | MXC_F_TMR_INTFL_TIMER1); // clear interrupt
mbed_official 514:7668256dbe61 204 NVIC_ClearPendingIRQ(US_TIMER_IRQn);
mbed_official 514:7668256dbe61 205 inc_current_cnt(US_TIMER->term_cnt32);
mbed_official 514:7668256dbe61 206 }
mbed_official 514:7668256dbe61 207
mbed_official 514:7668256dbe61 208 // add and reset the current count value
mbed_official 514:7668256dbe61 209 inc_current_cnt(US_TIMER->count32);
mbed_official 514:7668256dbe61 210 US_TIMER->count32 = 0;
mbed_official 514:7668256dbe61 211
mbed_official 514:7668256dbe61 212 // add the number of cycles that the timer is disabled here for
mbed_official 514:7668256dbe61 213 inc_current_cnt(200);
mbed_official 514:7668256dbe61 214
mbed_official 514:7668256dbe61 215 event_cnt = (uint64_t)timestamp * ticks_per_us;
mbed_official 514:7668256dbe61 216
mbed_official 514:7668256dbe61 217 // Check to see if the event has already passed
mbed_official 514:7668256dbe61 218 if (!event_passed(current_cnt, event_cnt)) {
mbed_official 514:7668256dbe61 219 uint64_t diff = event_diff(current_cnt, event_cnt);
mbed_official 514:7668256dbe61 220 if (diff < (uint64_t)0xFFFFFFFF) {
mbed_official 514:7668256dbe61 221 // the event occurs before the next overflow
mbed_official 514:7668256dbe61 222 US_TIMER->term_cnt32 = diff;
mbed_official 514:7668256dbe61 223 } else {
mbed_official 514:7668256dbe61 224 // the event occurs after the next overflow
mbed_official 514:7668256dbe61 225 US_TIMER->term_cnt32 = 0xFFFFFFFF; // set to max
mbed_official 514:7668256dbe61 226 }
mbed_official 514:7668256dbe61 227 } else {
mbed_official 514:7668256dbe61 228 // the requested timestamp occurs in the past
mbed_official 514:7668256dbe61 229 // set the timer up to immediately expire
mbed_official 514:7668256dbe61 230 US_TIMER->term_cnt32 = 1;
mbed_official 514:7668256dbe61 231 }
mbed_official 514:7668256dbe61 232 US_TIMER->ctrl |= MXC_F_TMR_CTRL_ENABLE0; // enable timer
mbed_official 514:7668256dbe61 233 }
mbed_official 514:7668256dbe61 234
mbed_official 514:7668256dbe61 235 //******************************************************************************
mbed_official 514:7668256dbe61 236 void us_ticker_disable_interrupt(void)
mbed_official 514:7668256dbe61 237 {
mbed_official 514:7668256dbe61 238 // There are no more events, set timer overflow to the max
mbed_official 514:7668256dbe61 239 US_TIMER->term_cnt32 = 0xFFFFFFFF;
mbed_official 514:7668256dbe61 240 }
mbed_official 514:7668256dbe61 241
mbed_official 514:7668256dbe61 242 //******************************************************************************
mbed_official 514:7668256dbe61 243 void us_ticker_clear_interrupt(void)
mbed_official 514:7668256dbe61 244 {
mbed_official 514:7668256dbe61 245 // cleared in the local handler
mbed_official 514:7668256dbe61 246 }
mbed_official 514:7668256dbe61 247
mbed_official 514:7668256dbe61 248 //******************************************************************************
mbed_official 514:7668256dbe61 249 void us_ticker_set(timestamp_t timestamp)
mbed_official 514:7668256dbe61 250 {
mbed_official 514:7668256dbe61 251 US_TIMER->ctrl &= ~MXC_F_TMR_CTRL_ENABLE0; // disable timer
mbed_official 514:7668256dbe61 252 current_cnt = (uint64_t)timestamp * ticks_per_us;
mbed_official 514:7668256dbe61 253 US_TIMER->count32 = 0;
mbed_official 514:7668256dbe61 254 US_TIMER->term_cnt32 = 0xFFFFFFFF;
mbed_official 514:7668256dbe61 255 US_TIMER->ctrl |= MXC_F_TMR_CTRL_ENABLE0; // enable timer
mbed_official 514:7668256dbe61 256
mbed_official 514:7668256dbe61 257 if (((uint64_t)timestamp * ticks_per_us) >= event_cnt) {
mbed_official 514:7668256dbe61 258 // The next timestamp has elapsed. Trigger the interrupt to handle it.
mbed_official 514:7668256dbe61 259 NVIC_SetPendingIRQ(US_TIMER_IRQn);
mbed_official 514:7668256dbe61 260 }
mbed_official 514:7668256dbe61 261 }