Johannes Stratmann / mbed-dev

added prescaler for 16 bit pwm in LPC1347 target

Fork of mbed-dev by mbed official

targets/cmsis/TARGET_ARM_SSG/TARGET_BEETLE/apb_timer.c@147:ba84b7dc41a7, 2016-09-10 (annotated)

Committer:
JojoS
Date:
Sat Sep 10 15:32:04 2016 +0000
Revision:
147:ba84b7dc41a7
Parent:
144:ef7eb2e8f9f7 
added prescaler for 16 bit timers (solution as in LPC11xx), default prescaler 31 for max 28 ms period time

Who changed what in which revision?

UserRevisionLine numberNew contents of line
<> 144:ef7eb2e8f9f7 1 /* mbed Microcontroller Library
<> 144:ef7eb2e8f9f7 2 * Copyright (c) 2016 ARM Limited
<> 144:ef7eb2e8f9f7 3 *
<> 144:ef7eb2e8f9f7 4 * Licensed under the Apache License, Version 2.0 (the "License");
<> 144:ef7eb2e8f9f7 5 * you may not use this file except in compliance with the License.
<> 144:ef7eb2e8f9f7 6 * You may obtain a copy of the License at
<> 144:ef7eb2e8f9f7 7 *
<> 144:ef7eb2e8f9f7 8 * http://www.apache.org/licenses/LICENSE-2.0
<> 144:ef7eb2e8f9f7 9 *
<> 144:ef7eb2e8f9f7 10 * Unless required by applicable law or agreed to in writing, software
<> 144:ef7eb2e8f9f7 11 * distributed under the License is distributed on an "AS IS" BASIS,
<> 144:ef7eb2e8f9f7 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
<> 144:ef7eb2e8f9f7 13 * See the License for the specific language governing permissions and
<> 144:ef7eb2e8f9f7 14 * limitations under the License.
<> 144:ef7eb2e8f9f7 15 */
<> 144:ef7eb2e8f9f7 16 #include "cmsis.h"
<> 144:ef7eb2e8f9f7 17 #include "apb_timer.h"
<> 144:ef7eb2e8f9f7 18
<> 144:ef7eb2e8f9f7 19 /* Timer Private Data */
<> 144:ef7eb2e8f9f7 20 typedef struct {
<> 144:ef7eb2e8f9f7 21 /* Timer Definition */
<> 144:ef7eb2e8f9f7 22 CMSDK_TIMER_TypeDef *timerN;
<> 144:ef7eb2e8f9f7 23 /* Timer IRQn */
<> 144:ef7eb2e8f9f7 24 uint32_t timerIRQn;
<> 144:ef7eb2e8f9f7 25 /* Timer Reload Value */
<> 144:ef7eb2e8f9f7 26 uint32_t timerReload;
<> 144:ef7eb2e8f9f7 27 /* Timer state */
<> 144:ef7eb2e8f9f7 28 uint32_t state;
<> 144:ef7eb2e8f9f7 29 } apb_timer_t;
<> 144:ef7eb2e8f9f7 30
<> 144:ef7eb2e8f9f7 31 /* Timer state definitions */
<> 144:ef7eb2e8f9f7 32 #define TIMER_INITIALIZED (1)
<> 144:ef7eb2e8f9f7 33 #define TIMER_ENABLED (1 << 1)
<> 144:ef7eb2e8f9f7 34
<> 144:ef7eb2e8f9f7 35 /*
<> 144:ef7eb2e8f9f7 36 * This Timer is written for MBED OS and keeps count
<> 144:ef7eb2e8f9f7 37 * of the ticks. All the elaboration logic is demanded
<> 144:ef7eb2e8f9f7 38 * to the upper layers.
<> 144:ef7eb2e8f9f7 39 */
<> 144:ef7eb2e8f9f7 40 #define TIMER_MAX_VALUE 0xFFFFFFFF
<> 144:ef7eb2e8f9f7 41 #define TIMER_TICKS_US (SystemCoreClock/1000000)
<> 144:ef7eb2e8f9f7 42
<> 144:ef7eb2e8f9f7 43 /* Timers Array */
<> 144:ef7eb2e8f9f7 44 static apb_timer_t Timers[NUM_TIMERS];
<> 144:ef7eb2e8f9f7 45
<> 144:ef7eb2e8f9f7 46 void Timer_Index_Init(uint32_t timer, uint32_t reload,
<> 144:ef7eb2e8f9f7 47 CMSDK_TIMER_TypeDef *TimerN, uint32_t IRQn)
<> 144:ef7eb2e8f9f7 48 {
<> 144:ef7eb2e8f9f7 49 Timers[timer].timerN = TimerN;
<> 144:ef7eb2e8f9f7 50 Timers[timer].timerIRQn = IRQn;
<> 144:ef7eb2e8f9f7 51 Timers[timer].timerReload = reload;
<> 144:ef7eb2e8f9f7 52 Timers[timer].state = TIMER_INITIALIZED;
<> 144:ef7eb2e8f9f7 53 }
<> 144:ef7eb2e8f9f7 54
<> 144:ef7eb2e8f9f7 55 /*
<> 144:ef7eb2e8f9f7 56 * Timer_Initialize(): Initializes an hardware timer
<> 144:ef7eb2e8f9f7 57 * timer: timer to be Initialized
<> 144:ef7eb2e8f9f7 58 * time_us: timer reload value in us - 0 to reload to timer max value
<> 144:ef7eb2e8f9f7 59 * time_us = tick_value / TIMER_TICKS_US
<> 144:ef7eb2e8f9f7 60 */
<> 144:ef7eb2e8f9f7 61 #define TIMER_INIT(index, reload) Timer_Index_Init(index, reload, CMSDK_TIMER##index, TIMER##index##_IRQn)
<> 144:ef7eb2e8f9f7 62 void Timer_Initialize(uint32_t timer, uint32_t time_us)
<> 144:ef7eb2e8f9f7 63 {
<> 144:ef7eb2e8f9f7 64 uint32_t reload = 0;
<> 144:ef7eb2e8f9f7 65
<> 144:ef7eb2e8f9f7 66 if (timer < NUM_TIMERS)
<> 144:ef7eb2e8f9f7 67 {
<> 144:ef7eb2e8f9f7 68 if (time_us == 0)
<> 144:ef7eb2e8f9f7 69 reload = TIMER_MAX_VALUE;
<> 144:ef7eb2e8f9f7 70 else
<> 144:ef7eb2e8f9f7 71 reload = (time_us) * TIMER_TICKS_US;
<> 144:ef7eb2e8f9f7 72
<> 144:ef7eb2e8f9f7 73 switch(timer) {
<> 144:ef7eb2e8f9f7 74 case 0: TIMER_INIT(0, reload);
<> 144:ef7eb2e8f9f7 75 break;
<> 144:ef7eb2e8f9f7 76 case 1: TIMER_INIT(1, reload);
<> 144:ef7eb2e8f9f7 77 break;
<> 144:ef7eb2e8f9f7 78 default: break;
<> 144:ef7eb2e8f9f7 79 }
<> 144:ef7eb2e8f9f7 80 }
<> 144:ef7eb2e8f9f7 81 }
<> 144:ef7eb2e8f9f7 82
<> 144:ef7eb2e8f9f7 83 /*
<> 144:ef7eb2e8f9f7 84 * Timer_Enable(): Enables a hardware timer
<> 144:ef7eb2e8f9f7 85 * timer: timer to be enabled
<> 144:ef7eb2e8f9f7 86 */
<> 144:ef7eb2e8f9f7 87 void Timer_Enable(uint32_t timer)
<> 144:ef7eb2e8f9f7 88 {
<> 144:ef7eb2e8f9f7 89 /* The timer has to be contained in a valid range */
<> 144:ef7eb2e8f9f7 90 if (timer < NUM_TIMERS) {
<> 144:ef7eb2e8f9f7 91 /* Timer has to be already initialized */
<> 144:ef7eb2e8f9f7 92 if (Timers[timer].state == TIMER_INITIALIZED) {
<> 144:ef7eb2e8f9f7 93 /* Disable Timer */
<> 144:ef7eb2e8f9f7 94 (Timers[timer].timerN)->CTRL = 0x0;
<> 144:ef7eb2e8f9f7 95 /* Reload Value */
<> 144:ef7eb2e8f9f7 96 (Timers[timer].timerN)->RELOAD = Timers[timer].timerReload;
<> 144:ef7eb2e8f9f7 97 /* Enable Interrupt */
<> 144:ef7eb2e8f9f7 98 (Timers[timer].timerN)->CTRL = CMSDK_TIMER_CTRL_IRQEN_Msk;
<> 144:ef7eb2e8f9f7 99 /* Enable Counter */
<> 144:ef7eb2e8f9f7 100 (Timers[timer].timerN)->CTRL |= CMSDK_TIMER_CTRL_EN_Msk;
<> 144:ef7eb2e8f9f7 101 /* Change timer state */
<> 144:ef7eb2e8f9f7 102 Timers[timer].state |= TIMER_ENABLED;
<> 144:ef7eb2e8f9f7 103 }
<> 144:ef7eb2e8f9f7 104 }
<> 144:ef7eb2e8f9f7 105 }
<> 144:ef7eb2e8f9f7 106
<> 144:ef7eb2e8f9f7 107 /*
<> 144:ef7eb2e8f9f7 108 * Timer_Disable(): Disables a hardware timer
<> 144:ef7eb2e8f9f7 109 * timer: timer to be disabled
<> 144:ef7eb2e8f9f7 110 */
<> 144:ef7eb2e8f9f7 111 void Timer_Disable(uint32_t timer)
<> 144:ef7eb2e8f9f7 112 {
<> 144:ef7eb2e8f9f7 113 /* The timer has to be contained in a valid range */
<> 144:ef7eb2e8f9f7 114 if (timer < NUM_TIMERS) {
<> 144:ef7eb2e8f9f7 115 /* Timer has to be already initialized and enabled */
<> 144:ef7eb2e8f9f7 116 if (Timers[timer].state == (TIMER_INITIALIZED | TIMER_ENABLED)) {
<> 144:ef7eb2e8f9f7 117 /* Disable Timer */
<> 144:ef7eb2e8f9f7 118 (Timers[timer].timerN)->CTRL = 0x0;
<> 144:ef7eb2e8f9f7 119 /* Change timer state */
<> 144:ef7eb2e8f9f7 120 Timers[timer].state = TIMER_INITIALIZED;
<> 144:ef7eb2e8f9f7 121 }
<> 144:ef7eb2e8f9f7 122 }
<> 144:ef7eb2e8f9f7 123 }
<> 144:ef7eb2e8f9f7 124
<> 144:ef7eb2e8f9f7 125 /*
<> 144:ef7eb2e8f9f7 126 * Timer_isEnabled(): verifies if a timer is enabled
<> 144:ef7eb2e8f9f7 127 * timer: timer to be verified
<> 144:ef7eb2e8f9f7 128 * @return: 0 disabled - 1 enabled
<> 144:ef7eb2e8f9f7 129 */
<> 144:ef7eb2e8f9f7 130 uint32_t Timer_isEnabled(uint32_t timer)
<> 144:ef7eb2e8f9f7 131 {
<> 144:ef7eb2e8f9f7 132 /* The timer has to be contained in a valid range */
<> 144:ef7eb2e8f9f7 133 if (timer < NUM_TIMERS) {
<> 144:ef7eb2e8f9f7 134 /* Timer has to be already initialized and enabled */
<> 144:ef7eb2e8f9f7 135 if (Timers[timer].state == (TIMER_INITIALIZED | TIMER_ENABLED))
<> 144:ef7eb2e8f9f7 136 return 1;
<> 144:ef7eb2e8f9f7 137 } else {
<> 144:ef7eb2e8f9f7 138 return 0;
<> 144:ef7eb2e8f9f7 139 }
<> 144:ef7eb2e8f9f7 140 return 0;
<> 144:ef7eb2e8f9f7 141 }
<> 144:ef7eb2e8f9f7 142
<> 144:ef7eb2e8f9f7 143 /*
<> 144:ef7eb2e8f9f7 144 * Timer_Read(): provides timer VALUE
<> 144:ef7eb2e8f9f7 145 * timer: timer to be read
<> 144:ef7eb2e8f9f7 146 * @return: timer VALUE us
<> 144:ef7eb2e8f9f7 147 */
<> 144:ef7eb2e8f9f7 148 uint32_t Timer_Read(uint32_t timer)
<> 144:ef7eb2e8f9f7 149 {
<> 144:ef7eb2e8f9f7 150 uint32_t return_value = 0;
<> 144:ef7eb2e8f9f7 151 /* Verify if the Timer is enabled */
<> 144:ef7eb2e8f9f7 152 if (Timer_isEnabled(timer) == 1) {
<> 144:ef7eb2e8f9f7 153 return_value = (Timers[timer].timerReload
<> 144:ef7eb2e8f9f7 154 - (Timers[timer].timerN)->VALUE)
<> 144:ef7eb2e8f9f7 155 / TIMER_TICKS_US;
<> 144:ef7eb2e8f9f7 156 }
<> 144:ef7eb2e8f9f7 157
<> 144:ef7eb2e8f9f7 158 return return_value;
<> 144:ef7eb2e8f9f7 159 }
<> 144:ef7eb2e8f9f7 160
<> 144:ef7eb2e8f9f7 161 /*
<> 144:ef7eb2e8f9f7 162 * Timer_SetInterrupt(): sets timer Interrupt
<> 144:ef7eb2e8f9f7 163 * timer: timer on which interrupt is set
<> 144:ef7eb2e8f9f7 164 * time_us: reloading time in us
<> 144:ef7eb2e8f9f7 165 */
<> 144:ef7eb2e8f9f7 166 void Timer_SetInterrupt(uint32_t timer, uint32_t time_us)
<> 144:ef7eb2e8f9f7 167 {
<> 144:ef7eb2e8f9f7 168 uint32_t load_time_us = 0;
<> 144:ef7eb2e8f9f7 169 /* Verify if the Timer is enabled */
<> 144:ef7eb2e8f9f7 170 if (Timer_isEnabled(timer) == 1) {
<> 144:ef7eb2e8f9f7 171 /* Disable Timer */
<> 144:ef7eb2e8f9f7 172 Timer_Disable(timer);
<> 144:ef7eb2e8f9f7 173 /* Enable Interrupt */
<> 144:ef7eb2e8f9f7 174 (Timers[timer].timerN)->CTRL = CMSDK_TIMER_CTRL_IRQEN_Msk;
<> 144:ef7eb2e8f9f7 175
<> 144:ef7eb2e8f9f7 176 /* Check time us condition */
<> 144:ef7eb2e8f9f7 177 if(time_us == TIMER_DEFAULT_RELOAD)
<> 144:ef7eb2e8f9f7 178 load_time_us = TIMER_MAX_VALUE;
<> 144:ef7eb2e8f9f7 179 else
<> 144:ef7eb2e8f9f7 180 load_time_us = time_us * TIMER_TICKS_US;
<> 144:ef7eb2e8f9f7 181
<> 144:ef7eb2e8f9f7 182 /* Initialize Timer Value */
<> 144:ef7eb2e8f9f7 183 Timers[timer].timerReload = load_time_us;
<> 144:ef7eb2e8f9f7 184 (Timers[timer].timerN)->RELOAD = Timers[timer].timerReload;
<> 144:ef7eb2e8f9f7 185 (Timers[timer].timerN)->VALUE = Timers[timer].timerReload;
<> 144:ef7eb2e8f9f7 186 /* Enable Counter */
<> 144:ef7eb2e8f9f7 187 (Timers[timer].timerN)->CTRL |= CMSDK_TIMER_CTRL_EN_Msk;
<> 144:ef7eb2e8f9f7 188 /* Change timer state */
<> 144:ef7eb2e8f9f7 189 Timers[timer].state |= TIMER_ENABLED;
<> 144:ef7eb2e8f9f7 190 }
<> 144:ef7eb2e8f9f7 191 }
<> 144:ef7eb2e8f9f7 192
<> 144:ef7eb2e8f9f7 193 /*
<> 144:ef7eb2e8f9f7 194 * Timer_DisableInterrupt(): disables timer interrupt
<> 144:ef7eb2e8f9f7 195 * timer: timer on which interrupt is disabled
<> 144:ef7eb2e8f9f7 196 */
<> 144:ef7eb2e8f9f7 197 void Timer_DisableInterrupt(uint32_t timer)
<> 144:ef7eb2e8f9f7 198 {
<> 144:ef7eb2e8f9f7 199 /* Verify if the Timer is enabled */
<> 144:ef7eb2e8f9f7 200 if (Timer_isEnabled(timer) == 1) {
<> 144:ef7eb2e8f9f7 201 /* Disable Interrupt */
<> 144:ef7eb2e8f9f7 202 (Timers[timer].timerN)->CTRL &= CMSDK_TIMER_CTRL_EN_Msk;
<> 144:ef7eb2e8f9f7 203 }
<> 144:ef7eb2e8f9f7 204 }
<> 144:ef7eb2e8f9f7 205
<> 144:ef7eb2e8f9f7 206 /*
<> 144:ef7eb2e8f9f7 207 * Timer_ClearInterrupt(): clear timer interrupt
<> 144:ef7eb2e8f9f7 208 * timer: timer on which interrupt needs to be cleared
<> 144:ef7eb2e8f9f7 209 */
<> 144:ef7eb2e8f9f7 210 void Timer_ClearInterrupt(uint32_t timer)
<> 144:ef7eb2e8f9f7 211 {
<> 144:ef7eb2e8f9f7 212 /* Verify if the Timer is enabled */
<> 144:ef7eb2e8f9f7 213 if (Timer_isEnabled(timer) == 1) {
<> 144:ef7eb2e8f9f7 214 /* Clear Interrupt */
<> 144:ef7eb2e8f9f7 215 (Timers[timer].timerN)->INTCLEAR = CMSDK_TIMER_INTCLEAR_Msk;
<> 144:ef7eb2e8f9f7 216 }
<> 144:ef7eb2e8f9f7 217 }
<> 144:ef7eb2e8f9f7 218
<> 144:ef7eb2e8f9f7 219 /*
<> 144:ef7eb2e8f9f7 220 * Timer_GetIRQn(): returns IRQn of a Timer
<> 144:ef7eb2e8f9f7 221 * timer: timer on which IRQn is defined - 0 if it is not defined
<> 144:ef7eb2e8f9f7 222 */
<> 144:ef7eb2e8f9f7 223 uint32_t Timer_GetIRQn(uint32_t timer)
<> 144:ef7eb2e8f9f7 224 {
<> 144:ef7eb2e8f9f7 225 /* Verify if the Timer is enabled */
<> 144:ef7eb2e8f9f7 226 if (Timer_isEnabled(timer) == 1) {
<> 144:ef7eb2e8f9f7 227 return Timers[timer].timerIRQn;
<> 144:ef7eb2e8f9f7 228 }
<> 144:ef7eb2e8f9f7 229 return 0;
<> 144:ef7eb2e8f9f7 230 }
<> 144:ef7eb2e8f9f7 231
<> 144:ef7eb2e8f9f7 232 /*
<> 144:ef7eb2e8f9f7 233 * Timer_GetTicksUS(): returns the number of Ticks per us
<> 144:ef7eb2e8f9f7 234 * timer: timer associated with the Ticks per us
<> 144:ef7eb2e8f9f7 235 * @return: Ticks per us - 0 if the timer is disables
<> 144:ef7eb2e8f9f7 236 */
<> 144:ef7eb2e8f9f7 237 uint32_t Timer_GetTicksUS(uint32_t timer)
<> 144:ef7eb2e8f9f7 238 {
<> 144:ef7eb2e8f9f7 239 /* Verify if the Timer is enabled */
<> 144:ef7eb2e8f9f7 240 if (Timer_isEnabled(timer) == 1) {
<> 144:ef7eb2e8f9f7 241 return TIMER_TICKS_US;
<> 144:ef7eb2e8f9f7 242 }
<> 144:ef7eb2e8f9f7 243 return 0;
<> 144:ef7eb2e8f9f7 244 }
<> 144:ef7eb2e8f9f7 245
<> 144:ef7eb2e8f9f7 246 /*
<> 144:ef7eb2e8f9f7 247 * Timer_GetReloadValue(): returns the load value of the selected
<> 144:ef7eb2e8f9f7 248 * timer.
<> 144:ef7eb2e8f9f7 249 * timer: timer associated with the Ticks per us
<> 144:ef7eb2e8f9f7 250 * @return: reload value of the selected singletimer
<> 144:ef7eb2e8f9f7 251 */
<> 144:ef7eb2e8f9f7 252 uint32_t Timer_GetReloadValue(uint32_t timer)
<> 144:ef7eb2e8f9f7 253 {
<> 144:ef7eb2e8f9f7 254 /* Verify if the Timer is enabled */
<> 144:ef7eb2e8f9f7 255 if (Timer_isEnabled(timer) == 1) {
<> 144:ef7eb2e8f9f7 256 if (timer == TIMER1)
<> 144:ef7eb2e8f9f7 257 return Timers[timer].timerReload / TIMER_TICKS_US;
<> 144:ef7eb2e8f9f7 258 else
<> 144:ef7eb2e8f9f7 259 return Timers[timer].timerReload / TIMER_TICKS_US;
<> 144:ef7eb2e8f9f7 260 }
<> 144:ef7eb2e8f9f7 261 return 0;
<> 144:ef7eb2e8f9f7 262 }