mbed library sources
Dependents: frdm_kl05z_gpio_test
Fork of mbed-src by
Diff: targets/cmsis/TARGET_STM/TARGET_NUCLEO_L152RE/stm32l1xx_wwdg.c
- Revision:
- 76:aeb1df146756
- Child:
- 80:66393a7b209d
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/targets/cmsis/TARGET_STM/TARGET_NUCLEO_L152RE/stm32l1xx_wwdg.c Mon Jan 27 14:30:07 2014 +0000 @@ -0,0 +1,313 @@ +/** + ****************************************************************************** + * @file stm32l1xx_wwdg.c + * @author MCD Application Team + * @version V1.2.0 + * @date 22-February-2013 + * @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 @32MHz (PCLK1): ~128us / ~65.6ms. + + ##### 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 2013 STMicroelectronics</center></h2> + * + * Licensed under MCD-ST Liberty SW License Agreement V2, (the "License"); + * You may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.st.com/software_license_agreement_liberty_v2 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + ****************************************************************************** + */ + +/* Includes ------------------------------------------------------------------*/ +#include "stm32l1xx_wwdg.h" +#include "stm32l1xx_rcc.h" + +/** @addtogroup STM32L1xx_StdPeriph_Driver + * @{ + */ + +/** @defgroup WWDG + * @brief WWDG driver modules + * @{ + */ + +/* Private typedef -----------------------------------------------------------*/ +/* Private define ------------------------------------------------------------*/ + +/* ----------- WWDG registers bit address in the alias region ----------- */ +#define WWDG_OFFSET (WWDG_BASE - PERIPH_BASE) + +/* Alias word address of EWI bit */ +#define CFR_OFFSET (WWDG_OFFSET + 0x04) +#define EWI_BitNumber 0x09 +#define CFR_EWI_BB (PERIPH_BB_BASE + (CFR_OFFSET * 32) + (EWI_BitNumber * 4)) + +/* --------------------- 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) +{ + *(__IO uint32_t *) CFR_EWI_BB = (uint32_t)ENABLE; +} + +/** + * @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****/