116 lines
3.8 KiB
C
116 lines
3.8 KiB
C
/******************************************************************************
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* The MIT License
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*
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* Copyright (c) 2010 Michael Hope.
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*
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* Permission is hereby granted, free of charge, to any person
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* obtaining a copy of this software and associated documentation
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* files (the "Software"), to deal in the Software without
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* restriction, including without limitation the rights to use, copy,
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* modify, merge, publish, distribute, sublicense, and/or sell copies
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* of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be
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* included in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*****************************************************************************/
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/**
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* @file libmaple/include/libmaple/iwdg.h
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* @author Michael Hope, Marti Bolivar <mbolivar@leaflabs.com>
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* @brief Independent watchdog support.
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*
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* To use the independent watchdog, first call iwdg_init() with the
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* appropriate prescaler and IWDG counter reload values for your
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* application. Afterwards, you must periodically call iwdg_feed()
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* before the IWDG counter reaches 0 to reset the counter to its
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* reload value. If you do not, the chip will reset.
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*
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* Once started, the independent watchdog cannot be turned off.
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*/
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#ifndef _LIBMAPLE_IWDG_H_
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#define _LIBMAPLE_IWDG_H_
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#ifdef __cplusplus
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extern "C"{
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#endif
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#include <libmaple/libmaple_types.h>
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/*
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* Register map
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*/
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/** Independent watchdog register map type. */
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typedef struct iwdg_reg_map {
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__io uint32 KR; /**< Key register. */
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__io uint32 PR; /**< Prescaler register. */
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__io uint32 RLR; /**< Reload register. */
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__io uint32 SR; /**< Status register */
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} iwdg_reg_map;
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/** Independent watchdog base pointer */
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#define IWDG_BASE ((struct iwdg_reg_map*)0x40003000)
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/*
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* Register bit definitions
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*/
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/* Key register */
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#define IWDG_KR_UNLOCK 0x5555
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#define IWDG_KR_FEED 0xAAAA
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#define IWDG_KR_START 0xCCCC
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/* Prescaler register */
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#define IWDG_PR_DIV_4 0x0
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#define IWDG_PR_DIV_8 0x1
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#define IWDG_PR_DIV_16 0x2
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#define IWDG_PR_DIV_32 0x3
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#define IWDG_PR_DIV_64 0x4
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#define IWDG_PR_DIV_128 0x5
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#define IWDG_PR_DIV_256 0x6
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/* Status register */
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#define IWDG_SR_RVU_BIT 1
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#define IWDG_SR_PVU_BIT 0
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#define IWDG_SR_RVU (1U << IWDG_SR_RVU_BIT)
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#define IWDG_SR_PVU (1U << IWDG_SR_PVU_BIT)
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/**
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* @brief Independent watchdog prescalers.
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*
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* These divide the 40 kHz IWDG clock.
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*/
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typedef enum iwdg_prescaler {
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IWDG_PRE_4 = IWDG_PR_DIV_4, /**< Divide by 4 */
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IWDG_PRE_8 = IWDG_PR_DIV_8, /**< Divide by 8 */
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IWDG_PRE_16 = IWDG_PR_DIV_16, /**< Divide by 16 */
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IWDG_PRE_32 = IWDG_PR_DIV_32, /**< Divide by 32 */
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IWDG_PRE_64 = IWDG_PR_DIV_64, /**< Divide by 64 */
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IWDG_PRE_128 = IWDG_PR_DIV_128, /**< Divide by 128 */
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IWDG_PRE_256 = IWDG_PR_DIV_256 /**< Divide by 256 */
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} iwdg_prescaler;
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void iwdg_init(iwdg_prescaler prescaler, uint16 reload);
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void iwdg_feed(void);
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#ifdef __cplusplus
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} // extern "C"
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#endif
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#endif
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