| Xmega IEC60730 Class B Library 1.0 |

All Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
classb_rtc_common.c
Go to the documentation of this file.
1 /* This file has been prepared for Doxygen automatic documentation generation.*/
2 /**
3 * \file
4 *
5 * \brief
6 * Driver for the RTC.
7 *
8 * \par Application note:
9 * AVR1610: Guide to IEC60730 Class B compliance with XMEGA
10 *
11 * \par Documentation
12 * For comprehensive code documentation, supported compilers, compiler
13 * settings and supported devices see readme.html
14 *
15 * \author
16 * Atmel Corporation: http://www.atmel.com \n
17 * Support email: avr@atmel.com
18 *
19 * Copyright (C) 2012 Atmel Corporation. All rights reserved.
20 *
21 * \page License
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions are met:
25 *
26 * 1. Redistributions of source code must retain the above copyright notice,
27 * this list of conditions and the following disclaimer.
28 *
29 * 2. Redistributions in binary form must reproduce the above copyright notice,
30 * this list of conditions and the following disclaimer in the documentation
31 * and/or other materials provided with the distribution.
32 *
33 * 3. The name of Atmel may not be used to endorse or promote products derived
34 * from this software without specific prior written permission.
35 *
36 * 4. This software may only be redistributed and used in connection with an
37 * Atmel AVR product.
38 *
39 * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
40 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
41 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
42 * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
43 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
44 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
45 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
46 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
47 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
48 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
49 * DAMAGE.
50 */
51
52
53 #include "classb_rtc_common.h"
54
55 //! \addtogroup rtc_driver
56 //@{
57
58 //! \internal \brief RTC32 Initialization.
59 //!
60 //! This function initializes the VBAT module and enables the oscillator used by the RTC32.
61 #if defined(RTC32) || defined(__DOXYGEN__)
62 void vbat_init(void)
63 {
64 // Reset the battery backup system
65 CCP = CCP_IOREG_gc;
66 VBAT.CTRL = VBAT_RESET_bm;
67
68 // Enable access to VBAT
69 VBAT.CTRL |= VBAT_ACCEN_bm;
70
71 // Choose 1024Hz oscillator output and enable crystal oscillator failure monitor
72 VBAT.CTRL |= VBAT_XOSCFDEN_bm | VBAT_XOSCSEL_bm;
73 /* This delay is needed to give the voltage in the backup system some
74 * time to stabilize before we turn on the oscillator. If we do not
75 * have this delay we may get a failure detection.
76 */
77 delay_us(200);
78
79 // Enable the crystal oscillator
80 VBAT.CTRL |= VBAT_XOSCEN_bm;
81
82 // Wait until the crystal oscillator ready flag is set
83 while (!(VBAT.STATUS & VBAT_XOSCRDY_bm));
84 }
85 #endif
86
87 //! \internal \brief This function waits until RTC synchronizes.
88 bool rtc_is_busy( void ) {
89 #ifdef RTC32
90 return RTC32.SYNCCTRL & RTC32_SYNCBUSY_bm;
91 #else
92 return RTC.STATUS & RTC_SYNCBUSY_bm;
93 #endif
94 }
95
96
97 //! \brief This function sets up the RTC to be used in Class B tests.
98 //!
99 //! The RTC oscillator is enabled, compare interrupts are configured and RTC is enabled.
100 void classb_rtc_setup() {
101 #ifdef RTC32
102 // If we use a device with RTC32 module, the VBAT system must be initialized before we use the RTC module
103 // This sets a 1024 Hz RTC32 from the 32.768 kHz crystal oscillator
104 vbat_init();
105 #else
106 // Use the RTC with 1024 Hz from internal 32.768 kHz RC oscillator
107 OSC.CTRL |= OSC_RC32KEN_bm;
108 while (!(OSC.STATUS & OSC_RC32KRDY_bm));
109 CLK.RTCCTRL = CLK_RTCSRC_RCOSC_gc | CLK_RTCEN_bm;
110 #endif
111
112 // Set up the RTC to generate compare interrupt after RTC_TICK_REF [classb_freq.h] ticks and start the RTC.
113 RTC_TEST.CTRL &= ~RTC_TEST_START_bm; // Stop RTC
114 while (rtc_is_busy());
115 RTC_TEST.PER = 0xffff; // Maximum 16bit period, for device compatibility
116 RTC_TEST.CNT = 0;
117 RTC_TEST.COMP = CLASSB_RTC_INT_PERIOD;
118 while (rtc_is_busy());
119 RTC_TEST.INTCTRL = RTC_TEST_COMPINTLVL_LO_gc;
120 RTC_TEST.INTFLAGS = RTC_TEST_COMPIF_bm;
121 // Start RTC
122 RTC_TEST.CTRL |= RTC_TEST_START_bm;
123 }
124
125 //! \brief This is the RTC compare interrupt.
126 //!
127 //! Actions required in Class B tests are implemented as callbacks. Note that this
128 //! requires a number of symbols to be defined, either in a header file or at the
129 //! compiler level.
130 //!
131 //! It is possible to add user-defined code to the RTC interrupt through
132 //! \ref CLASSB_ACTIONS_RTC().
133 ISR(RTC_TEST_COMP_vect) {
134
135 // Reset the RTC
136 while (rtc_is_busy());
137 RTC_TEST.CNT = 0;
138 // Wait until the RTC module is ready, then start the RTC timer.
139 while (rtc_is_busy());
140 RTC_TEST.CTRL |= RTC_TEST_START_bm;
141
142 #ifdef CLASSB_FREQ_TEST
143 classb_freq_callback();
144 #endif
145
146 #ifdef CLASSB_INT_MON
147 classb_intmon_callback();
148 #endif
149
150
151 // User-configurable actions
152 CLASSB_ACTIONS_RTC();
153 }
154
155 //@}