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Diff: targets/cmsis/TARGET_STM/TARGET_NUCLEO_F030R8/stm32f0xx_iwdg.c
- Revision:
- 76:aeb1df146756
- Child:
- 106:ced8cbb51063
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/cmsis/TARGET_STM/TARGET_NUCLEO_F030R8/stm32f0xx_iwdg.c Mon Jan 27 14:30:07 2014 +0000
@@ -0,0 +1,293 @@
+/**
+ ******************************************************************************
+ * @file stm32f0xx_iwdg.c
+ * @author MCD Application Team
+ * @version V1.3.0
+ * @date 16-January-2014
+ * @brief This file provides firmware functions to manage the following
+ * functionalities of the Independent watchdog (IWDG) peripheral:
+ * + Prescaler and Counter configuration
+ * + IWDG activation
+ * + Flag management
+ *
+ * @verbatim
+ *
+ ==============================================================================
+ ##### IWDG features #####
+ ==============================================================================
+ [..] The IWDG can be started by either software or hardware (configurable
+ through option byte).
+
+ [..] The IWDG is clocked by its own dedicated low-speed clock (LSI) and
+ thus stays active even if the main clock fails.
+ Once the IWDG is started, the LSI is forced ON and cannot be disabled
+ (LSI cannot be disabled too), and the counter starts counting down from
+ the reset value of 0xFFF. When it reaches the end of count value (0x000)
+ a system reset is generated.
+ The IWDG counter should be reloaded at regular intervals to prevent
+ an MCU reset.
+
+ [..] The IWDG is implemented in the VDD voltage domain that is still functional
+ in STOP and STANDBY mode (IWDG reset can wake-up from STANDBY).
+
+ [..] IWDGRST flag in RCC_CSR register can be used to inform when a IWDG
+ reset occurs.
+
+ [..] Min-max timeout value @40KHz (LSI): ~0.1ms / ~28.3s
+ The IWDG timeout may vary due to LSI frequency dispersion. STM32F0xx
+ devices provide the capability to measure the LSI frequency (LSI clock
+ should be seleted as RTC clock which is internally connected to TIM10 CH1
+ input capture). The measured value can be used to have an IWDG timeout with
+ an acceptable accuracy.
+ For more information, please refer to the STM32F0xx Reference manual.
+
+ ##### How to use this driver #####
+ ==============================================================================
+ [..] This driver allows to use IWDG peripheral with either window option enabled
+ or disabled. To do so follow one of the two procedures below.
+ (#) Window option is enabled:
+ (++) Start the IWDG using IWDG_Enable() function, when the IWDG is used
+ in software mode (no need to enable the LSI, it will be enabled
+ by hardware).
+ (++) Enable write access to IWDG_PR and IWDG_RLR registers using
+ IWDG_WriteAccessCmd(IWDG_WriteAccess_Enable) function.
+ (++) Configure the IWDG prescaler using IWDG_SetPrescaler() function.
+ (++) Configure the IWDG counter value using IWDG_SetReload() function.
+ This value will be loaded in the IWDG counter each time the counter
+ is reloaded, then the IWDG will start counting down from this value.
+ (++) Wait for the IWDG registers to be updated using IWDG_GetFlagStatus() function.
+ (++) Configure the IWDG refresh window using IWDG_SetWindowValue() function.
+
+ (#) Window option is disabled:
+ (++) Enable write access to IWDG_PR and IWDG_RLR registers using
+ IWDG_WriteAccessCmd(IWDG_WriteAccess_Enable) function.
+ (++) Configure the IWDG prescaler using IWDG_SetPrescaler() function.
+ (++) Configure the IWDG counter value using IWDG_SetReload() function.
+ This value will be loaded in the IWDG counter each time the counter
+ is reloaded, then the IWDG will start counting down from this value.
+ (++) Wait for the IWDG registers to be updated using IWDG_GetFlagStatus() function.
+ (++) reload the IWDG counter at regular intervals during normal operation
+ to prevent an MCU reset, using IWDG_ReloadCounter() function.
+ (++) Start the IWDG using IWDG_Enable() function, when the IWDG is used
+ in software mode (no need to enable the LSI, it will be enabled
+ by hardware).
+
+ @endverbatim
+ *
+ ******************************************************************************
+ * @attention
+ *
+ * <h2><center>© COPYRIGHT 2014 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 "stm32f0xx_iwdg.h"
+
+/** @addtogroup STM32F0xx_StdPeriph_Driver
+ * @{
+ */
+
+/** @defgroup IWDG
+ * @brief IWDG driver modules
+ * @{
+ */
+
+/* Private typedef -----------------------------------------------------------*/
+/* Private define ------------------------------------------------------------*/
+/* ---------------------- IWDG registers bit mask ----------------------------*/
+/* KR register bit mask */
+#define KR_KEY_RELOAD ((uint16_t)0xAAAA)
+#define KR_KEY_ENABLE ((uint16_t)0xCCCC)
+
+/* Private macro -------------------------------------------------------------*/
+/* Private variables ---------------------------------------------------------*/
+/* Private function prototypes -----------------------------------------------*/
+/* Private functions ---------------------------------------------------------*/
+
+/** @defgroup IWDG_Private_Functions
+ * @{
+ */
+
+/** @defgroup IWDG_Group1 Prescaler and Counter configuration functions
+ * @brief Prescaler and Counter configuration functions
+ *
+@verbatim
+ ==============================================================================
+ ##### Prescaler and Counter configuration functions #####
+ ==============================================================================
+
+@endverbatim
+ * @{
+ */
+
+/**
+ * @brief Enables or disables write access to IWDG_PR and IWDG_RLR registers.
+ * @param IWDG_WriteAccess: new state of write access to IWDG_PR and IWDG_RLR registers.
+ * This parameter can be one of the following values:
+ * @arg IWDG_WriteAccess_Enable: Enable write access to IWDG_PR and IWDG_RLR registers
+ * @arg IWDG_WriteAccess_Disable: Disable write access to IWDG_PR and IWDG_RLR registers
+ * @retval None
+ */
+void IWDG_WriteAccessCmd(uint16_t IWDG_WriteAccess)
+{
+ /* Check the parameters */
+ assert_param(IS_IWDG_WRITE_ACCESS(IWDG_WriteAccess));
+ IWDG->KR = IWDG_WriteAccess;
+}
+
+/**
+ * @brief Sets IWDG Prescaler value.
+ * @param IWDG_Prescaler: specifies the IWDG Prescaler value.
+ * This parameter can be one of the following values:
+ * @arg IWDG_Prescaler_4: IWDG prescaler set to 4
+ * @arg IWDG_Prescaler_8: IWDG prescaler set to 8
+ * @arg IWDG_Prescaler_16: IWDG prescaler set to 16
+ * @arg IWDG_Prescaler_32: IWDG prescaler set to 32
+ * @arg IWDG_Prescaler_64: IWDG prescaler set to 64
+ * @arg IWDG_Prescaler_128: IWDG prescaler set to 128
+ * @arg IWDG_Prescaler_256: IWDG prescaler set to 256
+ * @retval None
+ */
+void IWDG_SetPrescaler(uint8_t IWDG_Prescaler)
+{
+ /* Check the parameters */
+ assert_param(IS_IWDG_PRESCALER(IWDG_Prescaler));
+ IWDG->PR = IWDG_Prescaler;
+}
+
+/**
+ * @brief Sets IWDG Reload value.
+ * @param Reload: specifies the IWDG Reload value.
+ * This parameter must be a number between 0 and 0x0FFF.
+ * @retval None
+ */
+void IWDG_SetReload(uint16_t Reload)
+{
+ /* Check the parameters */
+ assert_param(IS_IWDG_RELOAD(Reload));
+ IWDG->RLR = Reload;
+}
+
+/**
+ * @brief Reloads IWDG counter with value defined in the reload register
+ * (write access to IWDG_PR and IWDG_RLR registers disabled).
+ * @param None
+ * @retval None
+ */
+void IWDG_ReloadCounter(void)
+{
+ IWDG->KR = KR_KEY_RELOAD;
+}
+
+
+/**
+ * @brief Sets the IWDG window value.
+ * @param WindowValue: specifies the window value to be compared to the downcounter.
+ * @retval None
+ */
+void IWDG_SetWindowValue(uint16_t WindowValue)
+{
+ /* Check the parameters */
+ assert_param(IS_IWDG_WINDOW_VALUE(WindowValue));
+ IWDG->WINR = WindowValue;
+}
+
+/**
+ * @}
+ */
+
+/** @defgroup IWDG_Group2 IWDG activation function
+ * @brief IWDG activation function
+ *
+@verbatim
+ ==============================================================================
+ ##### IWDG activation function #####
+ ==============================================================================
+
+@endverbatim
+ * @{
+ */
+
+/**
+ * @brief Enables IWDG (write access to IWDG_PR and IWDG_RLR registers disabled).
+ * @param None
+ * @retval None
+ */
+void IWDG_Enable(void)
+{
+ IWDG->KR = KR_KEY_ENABLE;
+}
+
+/**
+ * @}
+ */
+
+/** @defgroup IWDG_Group3 Flag management function
+ * @brief Flag management function
+ *
+@verbatim
+ ===============================================================================
+ ##### Flag management function #####
+ ===============================================================================
+
+@endverbatim
+ * @{
+ */
+
+/**
+ * @brief Checks whether the specified IWDG flag is set or not.
+ * @param IWDG_FLAG: specifies the flag to check.
+ * This parameter can be one of the following values:
+ * @arg IWDG_FLAG_PVU: Prescaler Value Update on going
+ * @arg IWDG_FLAG_RVU: Reload Value Update on going
+ * @arg IWDG_FLAG_WVU: Counter Window Value Update on going
+ * @retval The new state of IWDG_FLAG (SET or RESET).
+ */
+FlagStatus IWDG_GetFlagStatus(uint16_t IWDG_FLAG)
+{
+ FlagStatus bitstatus = RESET;
+ /* Check the parameters */
+ assert_param(IS_IWDG_FLAG(IWDG_FLAG));
+ if ((IWDG->SR & IWDG_FLAG) != (uint32_t)RESET)
+ {
+ bitstatus = SET;
+ }
+ else
+ {
+ bitstatus = RESET;
+ }
+ /* Return the flag status */
+ return bitstatus;
+}
+
+/**
+ * @}
+ */
+
+/**
+ * @}
+ */
+
+/**
+ * @}
+ */
+
+/**
+ * @}
+ */
+
+/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/