Diff: mbed-dev/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/TARGET_DELTA_DFCM_NNN40/rtc_api.c

Revision:

18:6a4db94011d3

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-dev/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/TARGET_DELTA_DFCM_NNN40/rtc_api.c	Sun May 14 23:18:57 2017 +0000
@@ -0,0 +1,71 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include "rtc_api.h"
+
+ 
+#define LFCLK_FREQUENCY         (32768UL)
+#define RTC0_COUNTER_PRESCALER  ((LFCLK_FREQUENCY/8) - 1)
+#define COMPARE_COUNTERTIME       (691200UL) //86400 x 8
+
+
+time_t	initTime;
+
+void rtc_init(void) {
+
+    NVIC_EnableIRQ(RTC0_IRQn);                                      // Enable Interrupt for the RTC in the core.
+    //NRF_RTC0->TASKS_STOP =1;
+    NRF_RTC0->PRESCALER     = RTC0_COUNTER_PRESCALER;               // Set prescaler to a TICK of RTC_FREQUENCY.
+    NRF_RTC0->CC[0]         = COMPARE_COUNTERTIME;                 // Compare0 after approx COMPARE_COUNTERTIME seconds.
+
+    // Enable COMPARE0 event and COMPARE0 interrupt:
+    NRF_RTC0->EVTENSET      = RTC_EVTENSET_COMPARE0_Msk;
+    NRF_RTC0->INTENSET      = RTC_INTENSET_COMPARE0_Msk;
+    NRF_RTC0->TASKS_START = 1;
+}
+
+void rtc_free(void) {
+    // [TODO]
+}
+
+/*
+ * Little check routine to see if the RTC has been enabled
+ *
+ * Clock Control Register
+ *  RTC_CCR[0] : 0 = Disabled, 1 = Enabled
+ *
+ */
+int rtc_isenabled(void) {
+    // [TODO] return(((NRF_RTC0->TASKS_START) & 0x01) != 0);
+}
+
+time_t rtc_read(void) {
+
+    time_t t = initTime;
+    t += (86400*NRF_RTC0->EVENTS_COMPARE[0]);
+    t += (int)((NRF_RTC0->COUNTER)/8);
+    return(t);
+}
+
+void rtc_write(time_t t) {
+    // Convert the time in to a tm
+
+    // Pause clock, and clear counter register (clears us count)
+    NRF_RTC0->TASKS_STOP = 1;
+
+    initTime = t;
+    // Restart clock
+    NRF_RTC0->TASKS_START = 1;
+}