1 /* mbed Microcontroller Library
2 * Copyright (c) 2006-2013 ARM Limited
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 #include "PeripheralPins.h"
19 static void init(void) {
21 SIM->SCGC6 |= SIM_SCGC6_RTC_MASK;
23 pinmap_pinout(PinMap_RTC[0].pin, PinMap_RTC); //Map RTC clk input (if not NC)
25 // select RTC clock source
26 SIM->SOPT1 &= ~SIM_SOPT1_OSC32KSEL_MASK;
27 SIM->SOPT1 |= SIM_SOPT1_OSC32KSEL(PinMap_RTC[0].peripheral);
33 //Configure the TSR. default value: 1
36 if (PinMap_RTC[0].pin == NC) { //Use OSC32K
37 RTC->CR |= RTC_CR_OSCE_MASK;
38 //delay for OSCE stabilization
39 for(int i=0; i<0x1000; i++) __NOP();
43 RTC->SR |= RTC_SR_TCE_MASK;
51 * Little check routine to see if the RTC has been enabled
52 * 0 = Disabled, 1 = Enabled
54 int rtc_isenabled(void) {
55 // even if the RTC module is enabled,
56 // as we use RTC_CLKIN and an external clock,
57 // we need to reconfigure the pins. That is why we
58 // call init() if the rtc is enabled
60 // if RTC not enabled return 0
61 SIM->SCGC5 |= SIM_SCGC5_PORTA_MASK;
62 SIM->SCGC6 |= SIM_SCGC6_RTC_MASK;
63 if ((RTC->SR & RTC_SR_TCE_MASK) == 0)
70 time_t rtc_read(void) {
74 void rtc_write(time_t t) {
76 RTC->SR &= ~RTC_SR_TCE_MASK;
78 // we do not write 0 into TSR
79 // to avoid invalid time
87 RTC->SR |= RTC_SR_TCE_MASK;