Johannes Stratmann / mbed-dev

added prescaler for 16 bit pwm in LPC1347 target

Fork of mbed-dev by mbed official

targets/hal/TARGET_NUVOTON/TARGET_NUC472/sleep.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) 2015-2016 Nuvoton
<> 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
<> 144:ef7eb2e8f9f7 17 #include "sleep_api.h"
<> 144:ef7eb2e8f9f7 18 #include "serial_api.h"
<> 144:ef7eb2e8f9f7 19 #include "lp_ticker_api.h"
<> 144:ef7eb2e8f9f7 20
<> 144:ef7eb2e8f9f7 21 #if DEVICE_SLEEP
<> 144:ef7eb2e8f9f7 22
<> 144:ef7eb2e8f9f7 23 #include "cmsis.h"
<> 144:ef7eb2e8f9f7 24 #include "device.h"
<> 144:ef7eb2e8f9f7 25 #include "objects.h"
<> 144:ef7eb2e8f9f7 26 #include "PeripheralPins.h"
<> 144:ef7eb2e8f9f7 27
<> 144:ef7eb2e8f9f7 28 void us_ticker_prepare_sleep(struct sleep_s *obj);
<> 144:ef7eb2e8f9f7 29 void us_ticker_wakeup_from_sleep(struct sleep_s *obj);
<> 144:ef7eb2e8f9f7 30 static void mbed_enter_sleep(struct sleep_s *obj);
<> 144:ef7eb2e8f9f7 31 static void mbed_exit_sleep(struct sleep_s *obj);
<> 144:ef7eb2e8f9f7 32
<> 144:ef7eb2e8f9f7 33 int serial_allow_powerdown(void);
<> 144:ef7eb2e8f9f7 34 int spi_allow_powerdown(void);
<> 144:ef7eb2e8f9f7 35 int i2c_allow_powerdown(void);
<> 144:ef7eb2e8f9f7 36 int pwmout_allow_powerdown(void);
<> 144:ef7eb2e8f9f7 37
<> 144:ef7eb2e8f9f7 38 /**
<> 144:ef7eb2e8f9f7 39 * Enter Idle mode.
<> 144:ef7eb2e8f9f7 40 */
<> 144:ef7eb2e8f9f7 41 void sleep(void)
<> 144:ef7eb2e8f9f7 42 {
<> 144:ef7eb2e8f9f7 43 struct sleep_s sleep_obj;
<> 144:ef7eb2e8f9f7 44 sleep_obj.powerdown = 0;
<> 144:ef7eb2e8f9f7 45 mbed_enter_sleep(&sleep_obj);
<> 144:ef7eb2e8f9f7 46 mbed_exit_sleep(&sleep_obj);
<> 144:ef7eb2e8f9f7 47 }
<> 144:ef7eb2e8f9f7 48
<> 144:ef7eb2e8f9f7 49 /**
<> 144:ef7eb2e8f9f7 50 * Enter Power-down mode while no peripheral is active; otherwise, enter Idle mode.
<> 144:ef7eb2e8f9f7 51 */
<> 144:ef7eb2e8f9f7 52 void deepsleep(void)
<> 144:ef7eb2e8f9f7 53 {
<> 144:ef7eb2e8f9f7 54 struct sleep_s sleep_obj;
<> 144:ef7eb2e8f9f7 55 sleep_obj.powerdown = 1;
<> 144:ef7eb2e8f9f7 56 mbed_enter_sleep(&sleep_obj);
<> 144:ef7eb2e8f9f7 57 mbed_exit_sleep(&sleep_obj);
<> 144:ef7eb2e8f9f7 58 }
<> 144:ef7eb2e8f9f7 59
<> 144:ef7eb2e8f9f7 60 static void mbed_enter_sleep(struct sleep_s *obj)
<> 144:ef7eb2e8f9f7 61 {
<> 144:ef7eb2e8f9f7 62 // Check if serial allows entering power-down mode
<> 144:ef7eb2e8f9f7 63 if (obj->powerdown) {
<> 144:ef7eb2e8f9f7 64 obj->powerdown = serial_allow_powerdown();
<> 144:ef7eb2e8f9f7 65 }
<> 144:ef7eb2e8f9f7 66 // Check if spi allows entering power-down mode
<> 144:ef7eb2e8f9f7 67 if (obj->powerdown) {
<> 144:ef7eb2e8f9f7 68 obj->powerdown = spi_allow_powerdown();
<> 144:ef7eb2e8f9f7 69 }
<> 144:ef7eb2e8f9f7 70 // Check if i2c allows entering power-down mode
<> 144:ef7eb2e8f9f7 71 if (obj->powerdown) {
<> 144:ef7eb2e8f9f7 72 obj->powerdown = i2c_allow_powerdown();
<> 144:ef7eb2e8f9f7 73 }
<> 144:ef7eb2e8f9f7 74 // Check if pwmout allows entering power-down mode
<> 144:ef7eb2e8f9f7 75 if (obj->powerdown) {
<> 144:ef7eb2e8f9f7 76 obj->powerdown = pwmout_allow_powerdown();
<> 144:ef7eb2e8f9f7 77 }
<> 144:ef7eb2e8f9f7 78 // TODO: Check if other peripherals allow entering power-down mode
<> 144:ef7eb2e8f9f7 79
<> 144:ef7eb2e8f9f7 80 obj->start_us = lp_ticker_read();
<> 144:ef7eb2e8f9f7 81 // Let us_ticker prepare for power-down or reject it.
<> 144:ef7eb2e8f9f7 82 us_ticker_prepare_sleep(obj);
<> 144:ef7eb2e8f9f7 83
<> 144:ef7eb2e8f9f7 84 // NOTE(STALE): To pass mbed-drivers test, timer requires to be fine-grained, so its implementation needs HIRC rather than LIRC/LXT as its clock source.
<> 144:ef7eb2e8f9f7 85 // But as CLK_PowerDown()/CLK_Idle() is called, HIRC will be disabled and timer cannot keep counting and alarm. To overcome the dilemma,
<> 144:ef7eb2e8f9f7 86 // just make CPU halt and compromise power saving.
<> 144:ef7eb2e8f9f7 87 // NOTE: As CLK_PowerDown()/CLK_Idle() is called, HIRC/HXT will be disabled in normal mode, but not in ICE mode. This may cause confusion in development.
<> 144:ef7eb2e8f9f7 88
<> 144:ef7eb2e8f9f7 89 if (obj->powerdown) { // Power-down mode (HIRC/HXT disabled, LIRC/LXT enabled)
<> 144:ef7eb2e8f9f7 90 SYS_UnlockReg();
<> 144:ef7eb2e8f9f7 91 CLK_PowerDown();
<> 144:ef7eb2e8f9f7 92 SYS_LockReg();
<> 144:ef7eb2e8f9f7 93 }
<> 144:ef7eb2e8f9f7 94 else { // CPU halt mode (HIRC/HXT enabled, LIRC/LXT enabled)
<> 144:ef7eb2e8f9f7 95 // NOTE: NUC472's CLK_Idle() will also disable HIRC/HXT.
<> 144:ef7eb2e8f9f7 96 SYS_UnlockReg();
<> 144:ef7eb2e8f9f7 97 SCB->SCR &= ~SCB_SCR_SLEEPDEEP_Msk;
<> 144:ef7eb2e8f9f7 98 CLK->PWRCTL &= ~CLK_PWRCTL_PDEN_Msk;
<> 144:ef7eb2e8f9f7 99 __WFI();
<> 144:ef7eb2e8f9f7 100 SYS_LockReg();
<> 144:ef7eb2e8f9f7 101 }
<> 144:ef7eb2e8f9f7 102 __NOP();
<> 144:ef7eb2e8f9f7 103 __NOP();
<> 144:ef7eb2e8f9f7 104 __NOP();
<> 144:ef7eb2e8f9f7 105 __NOP();
<> 144:ef7eb2e8f9f7 106
<> 144:ef7eb2e8f9f7 107 obj->end_us = lp_ticker_read();
<> 144:ef7eb2e8f9f7 108 obj->period_us = (obj->end_us > obj->start_us) ? (obj->end_us - obj->start_us) : (uint32_t) ((uint64_t) obj->end_us + 0xFFFFFFFFu - obj->start_us);
<> 144:ef7eb2e8f9f7 109 // Let us_ticker recover from power-down.
<> 144:ef7eb2e8f9f7 110 us_ticker_wakeup_from_sleep(obj);
<> 144:ef7eb2e8f9f7 111 }
<> 144:ef7eb2e8f9f7 112
<> 144:ef7eb2e8f9f7 113 static void mbed_exit_sleep(struct sleep_s *obj)
<> 144:ef7eb2e8f9f7 114 {
<> 144:ef7eb2e8f9f7 115 // TODO: TO BE CONTINUED
<> 144:ef7eb2e8f9f7 116
<> 144:ef7eb2e8f9f7 117 (void)obj;
<> 144:ef7eb2e8f9f7 118 }
<> 144:ef7eb2e8f9f7 119
<> 144:ef7eb2e8f9f7 120 #endif