| Christina Quast | 8be71e4 | 2014-12-02 13:06:01 +0100 | [diff] [blame] | 1 | /* ----------------------------------------------------------------------------
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| 2 | * ATMEL Microcontroller Software Support
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| 3 | * ----------------------------------------------------------------------------
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| 4 | * Copyright (c) 2009, Atmel Corporation
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| 5 | *
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| 6 | * All rights reserved.
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| 7 | *
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| 8 | * Redistribution and use in source and binary forms, with or without
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| 9 | * modification, are permitted provided that the following conditions are met:
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| 10 | *
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| 11 | * - Redistributions of source code must retain the above copyright notice,
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| 12 | * this list of conditions and the disclaimer below.
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| 13 | *
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| 14 | * Atmel's name may not be used to endorse or promote products derived from
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| 15 | * this software without specific prior written permission.
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| 16 | *
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| 17 | * DISCLAIMER: THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR
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| 18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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| 19 | * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
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| 20 | * DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT,
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| 21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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| 22 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
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| 23 | * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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| 24 | * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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| 25 | * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
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| 26 | * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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| 27 | * ----------------------------------------------------------------------------
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| 28 | */
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| 29 |
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| 30 | /**
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| 31 | * \file
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| 32 | *
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| 33 | * Implementation of Watchdog Timer (WDT) controller.
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| 34 | *
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| 35 | */
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| 36 |
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| 37 | /** \addtogroup wdt_module Working with WDT
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| 38 | * The WDT driver provides the interface to configure and use the WDT
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| 39 | * peripheral.
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| 40 | *
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| 41 | * The WDT can be used to prevent system lock-up if the software becomes
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| 42 | * trapped in a deadlock. It can generate a general reset or a processor
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| 43 | * reset only. It is clocked by slow clock divided by 128.
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| 44 | *
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| 45 | * The WDT is running at reset with 16 seconds watchdog period (slow clock at 32.768 kHz)
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| 46 | * and external reset generation enabled. The user must either disable it or
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| 47 | * reprogram it to meet the application requires.
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| 48 | *
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| 49 | * To use the WDT, the user could follow these few steps:
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| 50 | * <ul>
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| 51 | * <li>Enable watchdog with given mode using \ref WDT_Enable().
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| 52 | * <li>Restart the watchdog using \ref WDT_Restart() within the watchdog period.
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| 53 | * </ul>
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| 54 | *
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| 55 | * For more accurate information, please look at the WDT section of the
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| 56 | * Datasheet.
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| 57 | *
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| 58 | * \note
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| 59 | * The Watchdog Mode Register (WDT_MR) can be written only once.\n
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| 60 | *
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| 61 | * Related files :\n
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| 62 | * \ref wdt.c\n
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| 63 | * \ref wdt.h.\n
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| 64 | */
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| 65 | /*@{*/
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| 66 | /*@}*/
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| 67 |
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| 68 | /*---------------------------------------------------------------------------
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| 69 | * Headers
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| 70 | *---------------------------------------------------------------------------*/
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| 71 |
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| 72 | #include "chip.h"
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| 73 |
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| 74 | #include <stdint.h>
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| 75 |
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| 76 | /*----------------------------------------------------------------------------
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| 77 | * Exported functions
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| 78 | *----------------------------------------------------------------------------*/
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| 79 |
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| 80 | /**
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| 81 | * \brief Enable watchdog with given mode.
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| 82 | *
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| 83 | * \note The Watchdog Mode Register (WDT_MR) can be written only once.
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| 84 | * Only a processor reset resets it.
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| 85 | *
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| 86 | * \param dwMode WDT mode to be set
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| 87 | */
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| 88 | extern void WDT_Enable( Wdt* pWDT, uint32_t dwMode )
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| 89 | {
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| 90 | pWDT->WDT_MR = dwMode ;
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| 91 | }
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| 92 |
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| 93 | /**
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| 94 | * \brief Disable watchdog.
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| 95 | *
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| 96 | * \note The Watchdog Mode Register (WDT_MR) can be written only once.
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| 97 | * Only a processor reset resets it.
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| 98 | */
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| 99 | extern void WDT_Disable( Wdt* pWDT )
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| 100 | {
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| 101 | pWDT->WDT_MR = WDT_MR_WDDIS;
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| 102 | }
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| 103 |
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| 104 | /**
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| 105 | * \brief Watchdog restart.
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| 106 | */
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| 107 | extern void WDT_Restart( Wdt* pWDT )
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| 108 | {
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| 109 | pWDT->WDT_CR = 0xA5000001;
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| 110 | }
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| 111 |
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| 112 | /**
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| 113 | * \brief Watchdog get status.
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| 114 | */
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| 115 | extern uint32_t WDT_GetStatus( Wdt* pWDT )
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| 116 | {
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| 117 | return (pWDT->WDT_SR & 0x3) ;
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| 118 | }
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| 119 |
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| 120 | /**
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| 121 | * \brief Watchdog get period.
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| 122 | *
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| 123 | * \param dwMs desired watchdog period in millisecond.
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| 124 | */
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| 125 | extern uint32_t WDT_GetPeriod( uint32_t dwMs )
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| 126 | {
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| 127 | if ( (dwMs < 4) || (dwMs > 16000) )
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| 128 | {
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| 129 | return 0 ;
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| 130 | }
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| 131 | return ((dwMs << 8) / 1000) ;
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| 132 | }
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