diff options
Diffstat (limited to 'bsps/arm/stm32h7/hal/stm32h7xx_hal_iwdg.c')
| -rw-r--r-- | bsps/arm/stm32h7/hal/stm32h7xx_hal_iwdg.c | 84 |
1 files changed, 51 insertions, 33 deletions
diff --git a/bsps/arm/stm32h7/hal/stm32h7xx_hal_iwdg.c b/bsps/arm/stm32h7/hal/stm32h7xx_hal_iwdg.c index e65336a6bf..909042f554 100644 --- a/bsps/arm/stm32h7/hal/stm32h7xx_hal_iwdg.c +++ b/bsps/arm/stm32h7/hal/stm32h7xx_hal_iwdg.c @@ -8,6 +8,17 @@ * + Initialization and Start functions * + IO operation functions * + ****************************************************************************** + * @attention + * + * Copyright (c) 2017 STMicroelectronics. + * All rights reserved. + * + * This software is licensed under terms that can be found in the LICENSE file + * in the root directory of this software component. + * If no LICENSE file comes with this software, it is provided AS-IS. + * + ****************************************************************************** @verbatim ============================================================================== ##### IWDG Generic features ##### @@ -16,34 +27,44 @@ (+) The IWDG can be started by either software or hardware (configurable through option byte). - (+) The IWDG is clocked by Low-Speed clock (LSI) and thus stays active even - if the main clock fails. + (+) The IWDG is clocked by the Low-Speed Internal clock (LSI) and thus stays + active even if the main clock fails. - (+) Once the IWDG is started, the LSI is forced ON and both can not be + (+) Once the IWDG is started, the LSI is forced ON and both cannot be disabled. The counter starts counting down from the reset value (0xFFF). When it reaches the end of count value (0x000) a reset signal is generated (IWDG reset). (+) Whenever the key value 0x0000 AAAA is written in the IWDG_KR register, - the IWDG_RLR value is reloaded in the counter and the watchdog reset is - prevented. + the IWDG_RLR value is reloaded into the counter and the watchdog reset + is prevented. (+) 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). + in STOP and STANDBY mode (IWDG reset can wake up the CPU from STANDBY). IWDGRST flag in RCC_CSR register can be used to inform when an IWDG reset occurs. - (+) Debug mode : When the microcontroller enters debug mode (core halted), + (+) Debug mode: When the microcontroller enters debug mode (core halted), the IWDG counter either continues to work normally or stops, depending on DBG_IWDG_STOP configuration bit in DBG module, accessible through __HAL_DBGMCU_FREEZE_IWDG1() or __HAL_DBGMCU_FREEZE2_IWDG2() and __HAL_DBGMCU_UnFreeze_IWDG1 or __HAL_DBGMCU_UnFreeze2_IWDG2() macros. [..] Min-max timeout value @32KHz (LSI): ~125us / ~32.7s - The IWDG timeout may vary due to LSI frequency dispersion. STM32H7xx - devices provide the capability to measure the LSI frequency (LSI clock - connected internally to TIM16 CH1 input capture). The measured value - can be used to have an IWDG timeout with an acceptable accuracy. + The IWDG timeout may vary due to LSI clock frequency dispersion. + STM32H7xx devices provide the capability to measure the LSI clock + frequency (LSI clock is internally connected to TIM16 CH1 input capture). + The measured value can be used to have an IWDG timeout with an + acceptable accuracy. + + [..] Default timeout value (necessary for IWDG_SR status register update): + Constant LSI_VALUE is defined based on the nominal LSI clock frequency. + This frequency being subject to variations as mentioned above, the + default timeout value (defined through constant HAL_IWDG_DEFAULT_TIMEOUT + below) may become too short or too long. + In such cases, this default timeout value can be tuned by redefining + the constant LSI_VALUE at user-application level (based, for instance, + on the measured LSI clock frequency as explained above). ##### How to use this driver ##### ============================================================================== @@ -56,13 +77,13 @@ (++) Configure the IWDG prescaler and counter reload value. This reload value will be loaded in the IWDG counter each time the watchdog is reloaded, then the IWDG will start counting down from this value. - (++) Wait for status flags to be reset. (++) Depending on window parameter: (+++) If Window Init parameter is same as Window register value, nothing more is done but reload counter value in order to exit function with exact time base. (+++) Else modify Window register. This will automatically reload watchdog counter. + (++) Wait for status flags to be reset. (#) Then the application program must refresh the IWDG counter at regular intervals during normal operation to prevent an MCU reset, using @@ -77,18 +98,6 @@ the reload register @endverbatim - ****************************************************************************** - * @attention - * - * <h2><center>© Copyright (c) 2017 STMicroelectronics. - * All rights reserved.</center></h2> - * - * This software component is licensed by ST under BSD 3-Clause license, - * the "License"; You may not use this file except in compliance with the - * License. You may obtain a copy of the License at: - * opensource.org/licenses/BSD-3-Clause - * - ****************************************************************************** */ /* Includes ------------------------------------------------------------------*/ @@ -110,10 +119,17 @@ * @ingroup RTEMSBSPsARMSTM32H7 * @{ */ -/* Status register need 5 RC LSI divided by prescaler clock to be updated. With - higher prescaler (256), and according to LSI variation, we need to wait at - least 6 cycles so 48 ms. */ -#define HAL_IWDG_DEFAULT_TIMEOUT 48u +/* Status register needs up to 5 LSI clock periods divided by the clock + prescaler to be updated. The number of LSI clock periods is upper-rounded to + 6 for the timeout value calculation. + The timeout value is calculated using the highest prescaler (256) and + the LSI_VALUE constant. The value of this constant can be changed by the user + to take into account possible LSI clock period variations. + The timeout value is multiplied by 1000 to be converted in milliseconds. + LSI startup time is also considered here by adding LSI_STARTUP_TIME + converted in milliseconds. */ +#define HAL_IWDG_DEFAULT_TIMEOUT (((6UL * 256UL * 1000UL) / LSI_VALUE) + ((LSI_STARTUP_TIME / 1000UL) + 1UL)) +#define IWDG_KERNEL_UPDATE_FLAGS (IWDG_SR_WVU | IWDG_SR_RVU | IWDG_SR_PVU) /** * @} */ @@ -184,11 +200,14 @@ HAL_StatusTypeDef HAL_IWDG_Init(IWDG_HandleTypeDef *hiwdg) tickstart = HAL_GetTick(); /* Wait for register to be updated */ - while (hiwdg->Instance->SR != 0x00u) + while ((hiwdg->Instance->SR & IWDG_KERNEL_UPDATE_FLAGS) != 0x00u) { if ((HAL_GetTick() - tickstart) > HAL_IWDG_DEFAULT_TIMEOUT) { - return HAL_TIMEOUT; + if ((hiwdg->Instance->SR & IWDG_KERNEL_UPDATE_FLAGS) != 0x00u) + { + return HAL_TIMEOUT; + } } } @@ -211,6 +230,7 @@ HAL_StatusTypeDef HAL_IWDG_Init(IWDG_HandleTypeDef *hiwdg) return HAL_OK; } + /** * @} */ @@ -230,7 +250,6 @@ HAL_StatusTypeDef HAL_IWDG_Init(IWDG_HandleTypeDef *hiwdg) * @{ */ - /** * @brief Refresh the IWDG. * @param hiwdg pointer to a IWDG_HandleTypeDef structure that contains @@ -246,6 +265,7 @@ HAL_StatusTypeDef HAL_IWDG_Refresh(IWDG_HandleTypeDef *hiwdg) return HAL_OK; } + /** * @} */ @@ -262,5 +282,3 @@ HAL_StatusTypeDef HAL_IWDG_Refresh(IWDG_HandleTypeDef *hiwdg) /** * @} */ - -/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/ |