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| -rw-r--r-- | libmaple/iwdg.c | 56 | ||||
| -rw-r--r-- | libmaple/iwdg.h | 51 |
2 files changed, 107 insertions, 0 deletions
diff --git a/libmaple/iwdg.c b/libmaple/iwdg.c new file mode 100644 index 0000000..82a0151 --- /dev/null +++ b/libmaple/iwdg.c @@ -0,0 +1,56 @@ +/****************************************************************************** + * The MIT License + * + * Copyright (c) 2010 Michael Hope. + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + *****************************************************************************/ + +/** + * @file iwdg.c + * + * @brief Independent watchdog support + */ + +#include "libmaple.h" +#include "iwdg.h" + +#define IWDG_UNLOCK 0x5555 +#define IWDG_START 0xCCCC +#define IWDG_FEED 0xAAAA + +/** + * @brief Initialise and start the watchdog + * + * The prescaler and reload set the timeout. A prescaler of 3 divides + * the 40 kHz clock by 32 and gives roughly 1 ms per reload. + */ +void iwdg_init(uint8 prescaler, uint16 reload) { + __write(IWDG_KR, IWDG_UNLOCK); + __write(IWDG_PR, prescaler); + __write(IWDG_RLR, reload); + + /* Start things off */ + __write(IWDG_KR, IWDG_START); + __write(IWDG_KR, IWDG_FEED); +} + +void iwdg_feed(void) { + __write(IWDG_KR, IWDG_FEED); +} diff --git a/libmaple/iwdg.h b/libmaple/iwdg.h new file mode 100644 index 0000000..6002867 --- /dev/null +++ b/libmaple/iwdg.h @@ -0,0 +1,51 @@ +/****************************************************************************** + * The MIT License + * + * Copyright (c) 2010 Michael Hope. + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + *****************************************************************************/ + +/** + * @file iwdg.h + * + * @brief Independent watchdog support + */ + +#ifndef _IWDG_H_ +#define _IWDG_H_ + +#ifdef __cplusplus +extern "C"{ +#endif + +#define IWDG_BASE 0x40003000 +#define IWDG_KR (IWDG_BASE + 0x0) +#define IWDG_PR (IWDG_BASE + 0x4) +#define IWDG_RLR (IWDG_BASE + 0x8) +#define IWDG_SR (IWDG_BASE + 0xC) + +void iwdg_init(uint8 prescaler, uint16 reload); +void iwdg_feed(void); + +#ifdef __cplusplus +} // extern "C" +#endif + +#endif |