mbed library sources
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targets/cmsis/TARGET_STM/TARGET_STM32F3XX/stm32f30x_wwdg.c
- Committer:
- todotani
- Date:
- 2014-09-05
- Revision:
- 308:59cc78a25982
- Parent:
- 155:8435094ec241
File content as of revision 308:59cc78a25982:
/** ****************************************************************************** * @file stm32f30x_wwdg.c * @author MCD Application Team * @version V1.1.0 * @date 27-February-2014 * @brief This file provides firmware functions to manage the following * functionalities of the Window watchdog (WWDG) peripheral: * + Prescaler, Refresh window and Counter configuration * + WWDG activation * + Interrupts and flags management * * @verbatim * ============================================================================== ##### WWDG features ##### ============================================================================== [..] Once enabled the WWDG generates a system reset on expiry of a programmed time period, unless the program refreshes the counter (downcounter) before to reach 0x3F value (i.e. a reset is generated when the counter value rolls over from 0x40 to 0x3F). [..] An MCU reset is also generated if the counter value is refreshed before the counter has reached the refresh window value. This implies that the counter must be refreshed in a limited window. [..] Once enabled the WWDG cannot be disabled except by a system reset. [..] WWDGRST flag in RCC_CSR register can be used to inform when a WWDG reset occurs. [..] The WWDG counter input clock is derived from the APB clock divided by a programmable prescaler. [..] WWDG counter clock = PCLK1 / Prescaler. [..] WWDG timeout = (WWDG counter clock) * (counter value). [..] Min-max timeout value @36MHz (PCLK1): ~114us / ~58.3ms. ##### How to use this driver ##### ============================================================================== [..] (#) Enable WWDG clock using RCC_APB1PeriphClockCmd(RCC_APB1Periph_WWDG, ENABLE) function. (#) Configure the WWDG prescaler using WWDG_SetPrescaler() function. (#) Configure the WWDG refresh window using WWDG_SetWindowValue() function. (#) Set the WWDG counter value and start it using WWDG_Enable() function. When the WWDG is enabled the counter value should be configured to a value greater than 0x40 to prevent generating an immediate reset. (#) Optionally you can enable the Early wakeup interrupt which is generated when the counter reach 0x40. Once enabled this interrupt cannot be disabled except by a system reset. (#) Then the application program must refresh the WWDG counter at regular intervals during normal operation to prevent an MCU reset, using WWDG_SetCounter() function. This operation must occur only when the counter value is lower than the refresh window value, programmed using WWDG_SetWindowValue(). @endverbatim ****************************************************************************** * @attention * * <h2><center>© COPYRIGHT(c) 2014 STMicroelectronics</center></h2> * * Redistribution and use in source and binary forms, with or without modification, * are permitted provided that the following conditions are met: * 1. Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * 3. Neither the name of STMicroelectronics nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************** */ /* Includes ------------------------------------------------------------------*/ #include "stm32f30x_wwdg.h" #include "stm32f30x_rcc.h" /** @addtogroup STM32F30x_StdPeriph_Driver * @{ */ /** @defgroup WWDG * @brief WWDG driver modules * @{ */ /* Private typedef -----------------------------------------------------------*/ /* Private define ------------------------------------------------------------*/ /* --------------------- WWDG registers bit mask ---------------------------- */ /* CFR register bit mask */ #define CFR_WDGTB_MASK ((uint32_t)0xFFFFFE7F) #define CFR_W_MASK ((uint32_t)0xFFFFFF80) #define BIT_MASK ((uint8_t)0x7F) /* Private macro -------------------------------------------------------------*/ /* Private variables ---------------------------------------------------------*/ /* Private function prototypes -----------------------------------------------*/ /* Private functions ---------------------------------------------------------*/ /** @defgroup WWDG_Private_Functions * @{ */ /** @defgroup WWDG_Group1 Prescaler, Refresh window and Counter configuration functions * @brief Prescaler, Refresh window and Counter configuration functions * @verbatim ============================================================================== ##### Prescaler, Refresh window and Counter configuration functions ##### ============================================================================== @endverbatim * @{ */ /** * @brief Deinitializes the WWDG peripheral registers to their default reset values. * @param None * @retval None */ void WWDG_DeInit(void) { RCC_APB1PeriphResetCmd(RCC_APB1Periph_WWDG, ENABLE); RCC_APB1PeriphResetCmd(RCC_APB1Periph_WWDG, DISABLE); } /** * @brief Sets the WWDG Prescaler. * @param WWDG_Prescaler: specifies the WWDG Prescaler. * This parameter can be one of the following values: * @arg WWDG_Prescaler_1: WWDG counter clock = (PCLK1/4096)/1 * @arg WWDG_Prescaler_2: WWDG counter clock = (PCLK1/4096)/2 * @arg WWDG_Prescaler_4: WWDG counter clock = (PCLK1/4096)/4 * @arg WWDG_Prescaler_8: WWDG counter clock = (PCLK1/4096)/8 * @retval None */ void WWDG_SetPrescaler(uint32_t WWDG_Prescaler) { uint32_t tmpreg = 0; /* Check the parameters */ assert_param(IS_WWDG_PRESCALER(WWDG_Prescaler)); /* Clear WDGTB[1:0] bits */ tmpreg = WWDG->CFR & CFR_WDGTB_MASK; /* Set WDGTB[1:0] bits according to WWDG_Prescaler value */ tmpreg |= WWDG_Prescaler; /* Store the new value */ WWDG->CFR = tmpreg; } /** * @brief Sets the WWDG window value. * @param WindowValue: specifies the window value to be compared to the downcounter. * This parameter value must be lower than 0x80. * @retval None */ void WWDG_SetWindowValue(uint8_t WindowValue) { __IO uint32_t tmpreg = 0; /* Check the parameters */ assert_param(IS_WWDG_WINDOW_VALUE(WindowValue)); /* Clear W[6:0] bits */ tmpreg = WWDG->CFR & CFR_W_MASK; /* Set W[6:0] bits according to WindowValue value */ tmpreg |= WindowValue & (uint32_t) BIT_MASK; /* Store the new value */ WWDG->CFR = tmpreg; } /** * @brief Enables the WWDG Early Wakeup interrupt(EWI). * @note Once enabled this interrupt cannot be disabled except by a system reset. * @param None * @retval None */ void WWDG_EnableIT(void) { WWDG->CFR |= WWDG_CFR_EWI; } /** * @brief Sets the WWDG counter value. * @param Counter: specifies the watchdog counter value. * This parameter must be a number between 0x40 and 0x7F (to prevent generating * an immediate reset). * @retval None */ void WWDG_SetCounter(uint8_t Counter) { /* Check the parameters */ assert_param(IS_WWDG_COUNTER(Counter)); /* Write to T[6:0] bits to configure the counter value, no need to do a read-modify-write; writing a 0 to WDGA bit does nothing */ WWDG->CR = Counter & BIT_MASK; } /** * @} */ /** @defgroup WWDG_Group2 WWDG activation functions * @brief WWDG activation functions * @verbatim ============================================================================== ##### WWDG activation function ##### ============================================================================== @endverbatim * @{ */ /** * @brief Enables WWDG and load the counter value. * @param Counter: specifies the watchdog counter value. * This parameter must be a number between 0x40 and 0x7F (to prevent generating * an immediate reset). * @retval None */ void WWDG_Enable(uint8_t Counter) { /* Check the parameters */ assert_param(IS_WWDG_COUNTER(Counter)); WWDG->CR = WWDG_CR_WDGA | Counter; } /** * @} */ /** @defgroup WWDG_Group3 Interrupts and flags management functions * @brief Interrupts and flags management functions * @verbatim ============================================================================== ##### Interrupts and flags management functions ##### ============================================================================== @endverbatim * @{ */ /** * @brief Checks whether the Early Wakeup interrupt flag is set or not. * @param None * @retval The new state of the Early Wakeup interrupt flag (SET or RESET). */ FlagStatus WWDG_GetFlagStatus(void) { FlagStatus bitstatus = RESET; if ((WWDG->SR) != (uint32_t)RESET) { bitstatus = SET; } else { bitstatus = RESET; } return bitstatus; } /** * @brief Clears Early Wakeup interrupt flag. * @param None * @retval None */ void WWDG_ClearFlag(void) { WWDG->SR = (uint32_t)RESET; } /** * @} */ /** * @} */ /** * @} */ /** * @} */ /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/