SilentSensors / mbed-dev

Important changes to repositories hosted on mbed.com

Mbed hosted mercurial repositories are deprecated and are due to be permanently deleted in July 2026.

To keep a copy of this software download the repository Zip archive or clone locally using Mercurial.

It is also possible to export all your personal repositories from the account settings page.

Fork of mbed-dev by mbed official

targets/TARGET_NUVOTON/TARGET_NANO100/us_ticker.c@184:08ed48f1de7f, 2018-04-19 (annotated)

Committer:
AnnaBridge
Date:
Thu Apr 19 17:12:19 2018 +0100
Revision:
184:08ed48f1de7f
Parent:
182:a56a73fd2a6f
Child:
187:0387e8f68319
mbed-dev library. Release version 161

Who changed what in which revision?

UserRevisionLine numberNew contents of line
AnnaBridge 174:b96e65c34a4d 1 /* mbed Microcontroller Library
AnnaBridge 174:b96e65c34a4d 2 * Copyright (c) 2015-2017 Nuvoton
AnnaBridge 174:b96e65c34a4d 3 *
AnnaBridge 174:b96e65c34a4d 4 * Licensed under the Apache License, Version 2.0 (the "License");
AnnaBridge 174:b96e65c34a4d 5 * you may not use this file except in compliance with the License.
AnnaBridge 174:b96e65c34a4d 6 * You may obtain a copy of the License at
AnnaBridge 174:b96e65c34a4d 7 *
AnnaBridge 174:b96e65c34a4d 8 * http://www.apache.org/licenses/LICENSE-2.0
AnnaBridge 174:b96e65c34a4d 9 *
AnnaBridge 174:b96e65c34a4d 10 * Unless required by applicable law or agreed to in writing, software
AnnaBridge 174:b96e65c34a4d 11 * distributed under the License is distributed on an "AS IS" BASIS,
AnnaBridge 174:b96e65c34a4d 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
AnnaBridge 174:b96e65c34a4d 13 * See the License for the specific language governing permissions and
AnnaBridge 174:b96e65c34a4d 14 * limitations under the License.
AnnaBridge 174:b96e65c34a4d 15 */
AnnaBridge 182:a56a73fd2a6f 16
AnnaBridge 174:b96e65c34a4d 17 #include "us_ticker_api.h"
AnnaBridge 174:b96e65c34a4d 18 #include "sleep_api.h"
AnnaBridge 174:b96e65c34a4d 19 #include "mbed_assert.h"
AnnaBridge 174:b96e65c34a4d 20 #include "nu_modutil.h"
AnnaBridge 174:b96e65c34a4d 21 #include "nu_miscutil.h"
AnnaBridge 174:b96e65c34a4d 22
AnnaBridge 182:a56a73fd2a6f 23 /* Micro seconds per second */
AnnaBridge 182:a56a73fd2a6f 24 #define NU_US_PER_SEC 1000000
AnnaBridge 182:a56a73fd2a6f 25 /* Timer clock per us_ticker tick */
AnnaBridge 182:a56a73fd2a6f 26 #define NU_TMRCLK_PER_TICK 1
AnnaBridge 182:a56a73fd2a6f 27 /* Timer clock per second */
AnnaBridge 182:a56a73fd2a6f 28 #define NU_TMRCLK_PER_SEC (1000 * 1000)
AnnaBridge 182:a56a73fd2a6f 29 /* Timer max counter bit size */
AnnaBridge 182:a56a73fd2a6f 30 #define NU_TMR_MAXCNT_BITSIZE 24
AnnaBridge 182:a56a73fd2a6f 31 /* Timer max counter */
AnnaBridge 182:a56a73fd2a6f 32 #define NU_TMR_MAXCNT ((1 << NU_TMR_MAXCNT_BITSIZE) - 1)
AnnaBridge 174:b96e65c34a4d 33
AnnaBridge 182:a56a73fd2a6f 34 /* NOTE: Don't add static modifier here. These IRQ handler symbols are for linking.
AnnaBridge 182:a56a73fd2a6f 35 Vector table relocation is not actually supported for low-resource target. */
AnnaBridge 182:a56a73fd2a6f 36 void TMR0_IRQHandler(void);
AnnaBridge 174:b96e65c34a4d 37
AnnaBridge 182:a56a73fd2a6f 38 static const struct nu_modinit_s timer0_modinit = {TIMER_0, TMR0_MODULE, CLK_CLKSEL1_TMR0_S_HXT, 0, TMR0_RST, TMR0_IRQn, (void *) TMR0_IRQHandler};
AnnaBridge 182:a56a73fd2a6f 39
AnnaBridge 182:a56a73fd2a6f 40 #define TIMER_MODINIT timer0_modinit
AnnaBridge 182:a56a73fd2a6f 41
AnnaBridge 182:a56a73fd2a6f 42 static int ticker_inited = 0;
AnnaBridge 174:b96e65c34a4d 43
AnnaBridge 174:b96e65c34a4d 44 #define TMR_CMP_MIN 2
AnnaBridge 174:b96e65c34a4d 45 #define TMR_CMP_MAX 0xFFFFFFu
AnnaBridge 174:b96e65c34a4d 46
AnnaBridge 174:b96e65c34a4d 47 void us_ticker_init(void)
AnnaBridge 174:b96e65c34a4d 48 {
AnnaBridge 182:a56a73fd2a6f 49 if (ticker_inited) {
AnnaBridge 174:b96e65c34a4d 50 return;
AnnaBridge 174:b96e65c34a4d 51 }
AnnaBridge 182:a56a73fd2a6f 52 ticker_inited = 1;
AnnaBridge 182:a56a73fd2a6f 53
AnnaBridge 174:b96e65c34a4d 54 // Reset IP
AnnaBridge 182:a56a73fd2a6f 55 SYS_ResetModule(TIMER_MODINIT.rsetidx);
AnnaBridge 182:a56a73fd2a6f 56
AnnaBridge 174:b96e65c34a4d 57 // Select IP clock source
AnnaBridge 182:a56a73fd2a6f 58 CLK_SetModuleClock(TIMER_MODINIT.clkidx, TIMER_MODINIT.clksrc, TIMER_MODINIT.clkdiv);
AnnaBridge 182:a56a73fd2a6f 59
AnnaBridge 174:b96e65c34a4d 60 // Enable IP clock
AnnaBridge 182:a56a73fd2a6f 61 CLK_EnableModuleClock(TIMER_MODINIT.clkidx);
AnnaBridge 174:b96e65c34a4d 62
AnnaBridge 184:08ed48f1de7f 63 TIMER_T *timer_base = (TIMER_T *) NU_MODBASE(TIMER_MODINIT.modname);
AnnaBridge 184:08ed48f1de7f 64
AnnaBridge 174:b96e65c34a4d 65 // Timer for normal counter
AnnaBridge 184:08ed48f1de7f 66 uint32_t clk_timer = TIMER_GetModuleClock(timer_base);
AnnaBridge 182:a56a73fd2a6f 67 uint32_t prescale_timer = clk_timer / NU_TMRCLK_PER_SEC - 1;
AnnaBridge 182:a56a73fd2a6f 68 MBED_ASSERT((prescale_timer != (uint32_t) -1) && prescale_timer <= 127);
AnnaBridge 182:a56a73fd2a6f 69 MBED_ASSERT((clk_timer % NU_TMRCLK_PER_SEC) == 0);
AnnaBridge 182:a56a73fd2a6f 70 uint32_t cmp_timer = TMR_CMP_MAX;
AnnaBridge 182:a56a73fd2a6f 71 MBED_ASSERT(cmp_timer >= TMR_CMP_MIN && cmp_timer <= TMR_CMP_MAX);
AnnaBridge 184:08ed48f1de7f 72 timer_base->CTL = TIMER_CONTINUOUS_MODE;
AnnaBridge 184:08ed48f1de7f 73 timer_base->PRECNT = prescale_timer;
AnnaBridge 184:08ed48f1de7f 74 timer_base->CMPR = cmp_timer;
AnnaBridge 182:a56a73fd2a6f 75
AnnaBridge 182:a56a73fd2a6f 76 NVIC_SetVector(TIMER_MODINIT.irq_n, (uint32_t) TIMER_MODINIT.var);
AnnaBridge 182:a56a73fd2a6f 77
AnnaBridge 182:a56a73fd2a6f 78 NVIC_EnableIRQ(TIMER_MODINIT.irq_n);
AnnaBridge 182:a56a73fd2a6f 79
AnnaBridge 184:08ed48f1de7f 80 TIMER_EnableInt(timer_base);
AnnaBridge 184:08ed48f1de7f 81
AnnaBridge 184:08ed48f1de7f 82 TIMER_Start(timer_base);
AnnaBridge 184:08ed48f1de7f 83 /* Wait for timer to start counting and raise active flag */
AnnaBridge 184:08ed48f1de7f 84 while(! (timer_base->CTL & TIMER_CTL_TMR_ACT_Msk));
AnnaBridge 174:b96e65c34a4d 85 }
AnnaBridge 174:b96e65c34a4d 86
AnnaBridge 174:b96e65c34a4d 87 uint32_t us_ticker_read()
AnnaBridge 174:b96e65c34a4d 88 {
AnnaBridge 182:a56a73fd2a6f 89 if (! ticker_inited) {
AnnaBridge 174:b96e65c34a4d 90 us_ticker_init();
AnnaBridge 174:b96e65c34a4d 91 }
AnnaBridge 174:b96e65c34a4d 92
AnnaBridge 184:08ed48f1de7f 93 TIMER_T *timer_base = (TIMER_T *) NU_MODBASE(TIMER_MODINIT.modname);
AnnaBridge 174:b96e65c34a4d 94
AnnaBridge 182:a56a73fd2a6f 95 return (TIMER_GetCounter(timer_base) / NU_TMRCLK_PER_TICK);
AnnaBridge 174:b96e65c34a4d 96 }
AnnaBridge 174:b96e65c34a4d 97
AnnaBridge 174:b96e65c34a4d 98 void us_ticker_set_interrupt(timestamp_t timestamp)
AnnaBridge 174:b96e65c34a4d 99 {
AnnaBridge 182:a56a73fd2a6f 100 /* In continuous mode, counter will be reset to zero with the following sequence:
AnnaBridge 182:a56a73fd2a6f 101 * 1. Stop counting
AnnaBridge 182:a56a73fd2a6f 102 * 2. Configure new CMP value
AnnaBridge 182:a56a73fd2a6f 103 * 3. Restart counting
AnnaBridge 182:a56a73fd2a6f 104 *
AnnaBridge 182:a56a73fd2a6f 105 * This behavior is not what we want. To fix it, we could configure new CMP value
AnnaBridge 182:a56a73fd2a6f 106 * without stopping counting first.
AnnaBridge 182:a56a73fd2a6f 107 */
AnnaBridge 184:08ed48f1de7f 108 TIMER_T *timer_base = (TIMER_T *) NU_MODBASE(TIMER_MODINIT.modname);
AnnaBridge 182:a56a73fd2a6f 109
AnnaBridge 182:a56a73fd2a6f 110 /* NOTE: Because H/W timer requests min compare value, our implementation would have alarm delay of
AnnaBridge 182:a56a73fd2a6f 111 * (TMR_CMP_MIN - interval_clk) clocks when interval_clk is between [1, TMR_CMP_MIN). */
AnnaBridge 182:a56a73fd2a6f 112 uint32_t cmp_timer = timestamp * NU_TMRCLK_PER_TICK;
AnnaBridge 182:a56a73fd2a6f 113 cmp_timer = NU_CLAMP(cmp_timer, TMR_CMP_MIN, TMR_CMP_MAX);
AnnaBridge 182:a56a73fd2a6f 114 timer_base->CMPR = cmp_timer;
AnnaBridge 182:a56a73fd2a6f 115 }
AnnaBridge 182:a56a73fd2a6f 116
AnnaBridge 182:a56a73fd2a6f 117 void us_ticker_disable_interrupt(void)
AnnaBridge 182:a56a73fd2a6f 118 {
AnnaBridge 182:a56a73fd2a6f 119 TIMER_DisableInt((TIMER_T *) NU_MODBASE(TIMER_MODINIT.modname));
AnnaBridge 182:a56a73fd2a6f 120 }
AnnaBridge 182:a56a73fd2a6f 121
AnnaBridge 182:a56a73fd2a6f 122 void us_ticker_clear_interrupt(void)
AnnaBridge 182:a56a73fd2a6f 123 {
AnnaBridge 182:a56a73fd2a6f 124 TIMER_ClearIntFlag((TIMER_T *) NU_MODBASE(TIMER_MODINIT.modname));
AnnaBridge 174:b96e65c34a4d 125 }
AnnaBridge 174:b96e65c34a4d 126
AnnaBridge 174:b96e65c34a4d 127 void us_ticker_fire_interrupt(void)
AnnaBridge 174:b96e65c34a4d 128 {
AnnaBridge 182:a56a73fd2a6f 129 // NOTE: This event was in the past. Set the interrupt as pending, but don't process it here.
AnnaBridge 182:a56a73fd2a6f 130 // This prevents a recursive loop under heavy load which can lead to a stack overflow.
AnnaBridge 182:a56a73fd2a6f 131 NVIC_SetPendingIRQ(TIMER_MODINIT.irq_n);
AnnaBridge 182:a56a73fd2a6f 132 }
AnnaBridge 182:a56a73fd2a6f 133
AnnaBridge 182:a56a73fd2a6f 134 const ticker_info_t* us_ticker_get_info()
AnnaBridge 182:a56a73fd2a6f 135 {
AnnaBridge 182:a56a73fd2a6f 136 static const ticker_info_t info = {
AnnaBridge 182:a56a73fd2a6f 137 NU_TMRCLK_PER_SEC / NU_TMRCLK_PER_TICK,
AnnaBridge 182:a56a73fd2a6f 138 NU_TMR_MAXCNT_BITSIZE
AnnaBridge 182:a56a73fd2a6f 139 };
AnnaBridge 182:a56a73fd2a6f 140 return &info;
AnnaBridge 174:b96e65c34a4d 141 }
AnnaBridge 174:b96e65c34a4d 142
AnnaBridge 174:b96e65c34a4d 143 void TMR0_IRQHandler(void)
AnnaBridge 174:b96e65c34a4d 144 {
AnnaBridge 182:a56a73fd2a6f 145 TIMER_ClearIntFlag((TIMER_T *) NU_MODBASE(TIMER_MODINIT.modname));
AnnaBridge 174:b96e65c34a4d 146
AnnaBridge 182:a56a73fd2a6f 147 // NOTE: us_ticker_set_interrupt() may get called in us_ticker_irq_handler();
AnnaBridge 182:a56a73fd2a6f 148 us_ticker_irq_handler();
AnnaBridge 174:b96e65c34a4d 149 }