Johannes Stratmann / mbed-dev

added prescaler for 16 bit pwm in LPC1347 target

Fork of mbed-dev by mbed official

targets/hal/TARGET_NXP/TARGET_LPC43XX/rtc_api.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) 2006-2013 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 * Ported to NXP LPC43XX by Micromint USA <support@micromint.com>
<> 144:ef7eb2e8f9f7 17 */
<> 144:ef7eb2e8f9f7 18 #include "rtc_api.h"
<> 144:ef7eb2e8f9f7 19
<> 144:ef7eb2e8f9f7 20 // ensure rtc is running (unchanged if already running)
<> 144:ef7eb2e8f9f7 21
<> 144:ef7eb2e8f9f7 22 /* Setup the RTC based on a time structure, ensuring RTC is enabled
<> 144:ef7eb2e8f9f7 23 *
<> 144:ef7eb2e8f9f7 24 * Can be clocked by a 32.768KHz oscillator or prescale divider based on the APB clock
<> 144:ef7eb2e8f9f7 25 * - We want to use the 32khz clock, allowing for sleep mode
<> 144:ef7eb2e8f9f7 26 *
<> 144:ef7eb2e8f9f7 27 * Most registers are not changed by a Reset
<> 144:ef7eb2e8f9f7 28 * - We must initialize these registers between power-on and setting the RTC into operation
<> 144:ef7eb2e8f9f7 29
<> 144:ef7eb2e8f9f7 30 * Clock Control Register
<> 144:ef7eb2e8f9f7 31 * RTC_CCR[0] : Enable - 0 = Disabled, 1 = Enabled
<> 144:ef7eb2e8f9f7 32 * RTC_CCR[1] : Reset - 0 = Normal, 1 = Reset
<> 144:ef7eb2e8f9f7 33 * RTC_CCR[4] : Clock Source - 0 = Prescaler, 1 = 32k Xtal
<> 144:ef7eb2e8f9f7 34 *
<> 144:ef7eb2e8f9f7 35 * The RTC may already be running, so we should set it up
<> 144:ef7eb2e8f9f7 36 * without impacting if it is the case
<> 144:ef7eb2e8f9f7 37 */
<> 144:ef7eb2e8f9f7 38
<> 144:ef7eb2e8f9f7 39 void rtc_init(void) {
<> 144:ef7eb2e8f9f7 40 // Return, if already enabled
<> 144:ef7eb2e8f9f7 41 if (LPC_RTC->CCR & 1)
<> 144:ef7eb2e8f9f7 42 return;
<> 144:ef7eb2e8f9f7 43
<> 144:ef7eb2e8f9f7 44 // Enable 1kHz output of 32kHz oscillator
<> 144:ef7eb2e8f9f7 45 LPC_CREG->CREG0 &= ~((1 << 3) | (1 << 2));
<> 144:ef7eb2e8f9f7 46 LPC_CREG->CREG0 |= (0x03 << 6) | (1 << 1) | (1 << 0);
<> 144:ef7eb2e8f9f7 47
<> 144:ef7eb2e8f9f7 48 // Enable RTC
<> 144:ef7eb2e8f9f7 49 do {
<> 144:ef7eb2e8f9f7 50 LPC_RTC->CCR |= 1 << 0;
<> 144:ef7eb2e8f9f7 51 } while ((LPC_RTC->CCR & 1) == 0);
<> 144:ef7eb2e8f9f7 52 }
<> 144:ef7eb2e8f9f7 53
<> 144:ef7eb2e8f9f7 54 void rtc_free(void) {
<> 144:ef7eb2e8f9f7 55 // [TODO]
<> 144:ef7eb2e8f9f7 56 }
<> 144:ef7eb2e8f9f7 57
<> 144:ef7eb2e8f9f7 58 /*
<> 144:ef7eb2e8f9f7 59 * Little check routine to see if the RTC has been enabled
<> 144:ef7eb2e8f9f7 60 *
<> 144:ef7eb2e8f9f7 61 * Clock Control Register
<> 144:ef7eb2e8f9f7 62 * RTC_CCR[0] : 0 = Disabled, 1 = Enabled
<> 144:ef7eb2e8f9f7 63 *
<> 144:ef7eb2e8f9f7 64 */
<> 144:ef7eb2e8f9f7 65 int rtc_isenabled(void) {
<> 144:ef7eb2e8f9f7 66 return(((LPC_RTC->CCR) & 0x01) != 0);
<> 144:ef7eb2e8f9f7 67 }
<> 144:ef7eb2e8f9f7 68
<> 144:ef7eb2e8f9f7 69 /*
<> 144:ef7eb2e8f9f7 70 * RTC Registers
<> 144:ef7eb2e8f9f7 71 * RTC_SEC Seconds 0-59
<> 144:ef7eb2e8f9f7 72 * RTC_MIN Minutes 0-59
<> 144:ef7eb2e8f9f7 73 * RTC_HOUR Hour 0-23
<> 144:ef7eb2e8f9f7 74 * RTC_DOM Day of Month 1-28..31
<> 144:ef7eb2e8f9f7 75 * RTC_DOW Day of Week 0-6
<> 144:ef7eb2e8f9f7 76 * RTC_DOY Day of Year 1-365
<> 144:ef7eb2e8f9f7 77 * RTC_MONTH Month 1-12
<> 144:ef7eb2e8f9f7 78 * RTC_YEAR Year 0-4095
<> 144:ef7eb2e8f9f7 79 *
<> 144:ef7eb2e8f9f7 80 * struct tm
<> 144:ef7eb2e8f9f7 81 * tm_sec seconds after the minute 0-61
<> 144:ef7eb2e8f9f7 82 * tm_min minutes after the hour 0-59
<> 144:ef7eb2e8f9f7 83 * tm_hour hours since midnight 0-23
<> 144:ef7eb2e8f9f7 84 * tm_mday day of the month 1-31
<> 144:ef7eb2e8f9f7 85 * tm_mon months since January 0-11
<> 144:ef7eb2e8f9f7 86 * tm_year years since 1900
<> 144:ef7eb2e8f9f7 87 * tm_wday days since Sunday 0-6
<> 144:ef7eb2e8f9f7 88 * tm_yday days since January 1 0-365
<> 144:ef7eb2e8f9f7 89 * tm_isdst Daylight Saving Time flag
<> 144:ef7eb2e8f9f7 90 */
<> 144:ef7eb2e8f9f7 91 time_t rtc_read(void) {
<> 144:ef7eb2e8f9f7 92 // Setup a tm structure based on the RTC
<> 144:ef7eb2e8f9f7 93 struct tm timeinfo;
<> 144:ef7eb2e8f9f7 94 timeinfo.tm_sec = LPC_RTC->TIME[RTC_TIMETYPE_SECOND];
<> 144:ef7eb2e8f9f7 95 timeinfo.tm_min = LPC_RTC->TIME[RTC_TIMETYPE_MINUTE];
<> 144:ef7eb2e8f9f7 96 timeinfo.tm_hour = LPC_RTC->TIME[RTC_TIMETYPE_HOUR];
<> 144:ef7eb2e8f9f7 97 timeinfo.tm_mday = LPC_RTC->TIME[RTC_TIMETYPE_DAYOFMONTH];
<> 144:ef7eb2e8f9f7 98 timeinfo.tm_wday = LPC_RTC->TIME[RTC_TIMETYPE_DAYOFWEEK];
<> 144:ef7eb2e8f9f7 99 timeinfo.tm_yday = LPC_RTC->TIME[RTC_TIMETYPE_DAYOFYEAR];
<> 144:ef7eb2e8f9f7 100 timeinfo.tm_mon = LPC_RTC->TIME[RTC_TIMETYPE_MONTH] - 1;
<> 144:ef7eb2e8f9f7 101 timeinfo.tm_year = LPC_RTC->TIME[RTC_TIMETYPE_YEAR] - 1900;
<> 144:ef7eb2e8f9f7 102
<> 144:ef7eb2e8f9f7 103 // Convert to timestamp
<> 144:ef7eb2e8f9f7 104 time_t t = mktime(&timeinfo);
<> 144:ef7eb2e8f9f7 105
<> 144:ef7eb2e8f9f7 106 return t;
<> 144:ef7eb2e8f9f7 107 }
<> 144:ef7eb2e8f9f7 108
<> 144:ef7eb2e8f9f7 109 void rtc_write(time_t t) {
<> 144:ef7eb2e8f9f7 110 // Convert the time in to a tm
<> 144:ef7eb2e8f9f7 111 struct tm *timeinfo = localtime(&t);
<> 144:ef7eb2e8f9f7 112
<> 144:ef7eb2e8f9f7 113 // Pause clock, and clear counter register (clears us count)
<> 144:ef7eb2e8f9f7 114 LPC_RTC->CCR |= 2;
<> 144:ef7eb2e8f9f7 115
<> 144:ef7eb2e8f9f7 116 // Set the RTC
<> 144:ef7eb2e8f9f7 117 LPC_RTC->TIME[RTC_TIMETYPE_SECOND] = timeinfo->tm_sec;
<> 144:ef7eb2e8f9f7 118 LPC_RTC->TIME[RTC_TIMETYPE_MINUTE] = timeinfo->tm_min;
<> 144:ef7eb2e8f9f7 119 LPC_RTC->TIME[RTC_TIMETYPE_HOUR] = timeinfo->tm_hour;
<> 144:ef7eb2e8f9f7 120 LPC_RTC->TIME[RTC_TIMETYPE_DAYOFMONTH] = timeinfo->tm_mday;
<> 144:ef7eb2e8f9f7 121 LPC_RTC->TIME[RTC_TIMETYPE_DAYOFWEEK] = timeinfo->tm_wday;
<> 144:ef7eb2e8f9f7 122 LPC_RTC->TIME[RTC_TIMETYPE_DAYOFYEAR] = timeinfo->tm_yday;
<> 144:ef7eb2e8f9f7 123 LPC_RTC->TIME[RTC_TIMETYPE_MONTH] = timeinfo->tm_mon + 1;
<> 144:ef7eb2e8f9f7 124 LPC_RTC->TIME[RTC_TIMETYPE_YEAR] = timeinfo->tm_year + 1900;
<> 144:ef7eb2e8f9f7 125
<> 144:ef7eb2e8f9f7 126 // Restart clock
<> 144:ef7eb2e8f9f7 127 LPC_RTC->CCR &= ~((uint32_t)2);
<> 144:ef7eb2e8f9f7 128 }