--- /dev/null
+/**
+ ******************************************************************************
+ * @file stm32f4xx_rng.c
+ * @author MCD Application Team
+ * @version V1.0.0RC1
+ * @date 25-August-2011
+ * @brief This file provides firmware functions to manage the following
+ * functionalities of the Random Number Generator (RNG) peripheral:
+ * - Initialization and Configuration
+ * - Get 32 bit Random number
+ * - Interrupts and flags management
+ *
+ * @verbatim
+ *
+ * ===================================================================
+ * How to use this driver
+ * ===================================================================
+ * 1. Enable The RNG controller clock using
+ * RCC_AHB2PeriphClockCmd(RCC_AHB2Periph_RNG, ENABLE) function.
+ *
+ * 2. Activate the RNG peripheral using RNG_Cmd() function.
+ *
+ * 3. Wait until the 32 bit Random number Generator contains a valid
+ * random data (using polling/interrupt mode). For more details,
+ * refer to "Interrupts and flags management functions" module
+ * description.
+ *
+ * 4. Get the 32 bit Random number using RNG_GetRandomNumber() function
+ *
+ * 5. To get another 32 bit Random number, go to step 3.
+ *
+ *
+ *
+ * @endverbatim
+ *
+ ******************************************************************************
+ * @attention
+ *
+ * THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS
+ * WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE
+ * TIME. AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY
+ * DIRECT, INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING
+ * FROM THE CONTENT OF SUCH FIRMWARE AND/OR THE USE MADE BY CUSTOMERS OF THE
+ * CODING INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
+ *
+ * <h2><center>© COPYRIGHT 2011 STMicroelectronics</center></h2>
+ ******************************************************************************
+ */
+
+/* Includes ------------------------------------------------------------------*/
+#include "stm32f4xx_rng.h"
+#include "stm32f4xx_rcc.h"
+
+/** @addtogroup STM32F4xx_StdPeriph_Driver
+ * @{
+ */
+
+/** @defgroup RNG
+ * @brief RNG driver modules
+ * @{
+ */
+
+/* Private typedef -----------------------------------------------------------*/
+/* Private define ------------------------------------------------------------*/
+/* Private macro -------------------------------------------------------------*/
+/* Private variables ---------------------------------------------------------*/
+/* Private function prototypes -----------------------------------------------*/
+/* Private functions ---------------------------------------------------------*/
+
+/** @defgroup RNG_Private_Functions
+ * @{
+ */
+
+/** @defgroup RNG_Group1 Initialization and Configuration functions
+ * @brief Initialization and Configuration functions
+ *
+@verbatim
+ ===============================================================================
+ Initialization and Configuration functions
+ ===============================================================================
+ This section provides functions allowing to
+ - Initialize the RNG peripheral
+ - Enable or disable the RNG peripheral
+
+@endverbatim
+ * @{
+ */
+
+/**
+ * @brief Deinitializes the RNG peripheral registers to their default reset values.
+ * @param None
+ * @retval None
+ */
+void RNG_DeInit(void)
+{
+ /* Enable RNG reset state */
+ RCC_AHB2PeriphResetCmd(RCC_AHB2Periph_RNG, ENABLE);
+
+ /* Release RNG from reset state */
+ RCC_AHB2PeriphResetCmd(RCC_AHB2Periph_RNG, DISABLE);
+}
+
+/**
+ * @brief Enables or disables the RNG peripheral.
+ * @param NewState: new state of the RNG peripheral.
+ * This parameter can be: ENABLE or DISABLE.
+ * @retval None
+ */
+void RNG_Cmd(FunctionalState NewState)
+{
+ /* Check the parameters */
+ assert_param(IS_FUNCTIONAL_STATE(NewState));
+
+ if (NewState != DISABLE)
+ {
+ /* Enable the RNG */
+ RNG->CR |= RNG_CR_RNGEN;
+ }
+ else
+ {
+ /* Disable the RNG */
+ RNG->CR &= ~RNG_CR_RNGEN;
+ }
+}
+/**
+ * @}
+ */
+
+/** @defgroup RNG_Group2 Get 32 bit Random number function
+ * @brief Get 32 bit Random number function
+ *
+
+@verbatim
+ ===============================================================================
+ Get 32 bit Random number function
+ ===============================================================================
+ This section provides a function allowing to get the 32 bit Random number
+
+ @note Before to call this function you have to wait till DRDY flag is set,
+ using RNG_GetFlagStatus(RNG_FLAG_DRDY) function.
+
+@endverbatim
+ * @{
+ */
+
+
+/**
+ * @brief Returns a 32-bit random number.
+ *
+ * @note Before to call this function you have to wait till DRDY (data ready)
+ * flag is set, using RNG_GetFlagStatus(RNG_FLAG_DRDY) function.
+ * @note Each time the the Random number data is read (using RNG_GetRandomNumber()
+ * function), the RNG_FLAG_DRDY flag is automatically cleared.
+ * @note In the case of a seed error, the generation of random numbers is
+ * interrupted for as long as the SECS bit is '1'. If a number is
+ * available in the RNG_DR register, it must not be used because it may
+ * not have enough entropy. In this case, it is recommended to clear the
+ * SEIS bit(using RNG_ClearFlag(RNG_FLAG_SECS) function), then disable
+ * and enable the RNG peripheral (using RNG_Cmd() function) to
+ * reinitialize and restart the RNG.
+ * @note In the case of a clock error, the RNG is no more able to generate
+ * random numbers because the PLL48CLK clock is not correct. User have
+ * to check that the clock controller is correctly configured to provide
+ * the RNG clock and clear the CEIS bit (using RNG_ClearFlag(RNG_FLAG_CECS)
+ * function) . The clock error has no impact on the previously generated
+ * random numbers, and the RNG_DR register contents can be used.
+ *
+ * @param None
+ * @retval 32-bit random number.
+ */
+uint32_t RNG_GetRandomNumber(void)
+{
+ /* Return the 32 bit random number from the DR register */
+ return RNG->DR;
+}
+
+
+/**
+ * @}
+ */
+
+/** @defgroup RNG_Group3 Interrupts and flags management functions
+ * @brief Interrupts and flags management functions
+ *
+@verbatim
+ ===============================================================================
+ Interrupts and flags management functions
+ ===============================================================================
+
+ This section provides functions allowing to configure the RNG Interrupts and
+ to get the status and clear flags and Interrupts pending bits.
+
+ The RNG provides 3 Interrupts sources and 3 Flags:
+
+ Flags :
+ ----------
+ 1. RNG_FLAG_DRDY : In the case of the RNG_DR register contains valid
+ random data. it is cleared by reading the valid data
+ (using RNG_GetRandomNumber() function).
+
+ 2. RNG_FLAG_CECS : In the case of a seed error detection.
+
+ 3. RNG_FLAG_SECS : In the case of a clock error detection.
+
+
+ Interrupts :
+ ------------
+ if enabled, an RNG interrupt is pending :
+
+ 1. In the case of the RNG_DR register contains valid random data.
+ This interrupt source is cleared once the RNG_DR register has been read
+ (using RNG_GetRandomNumber() function) until a new valid value is
+ computed.
+
+ or
+ 2. In the case of a seed error : One of the following faulty sequences has
+ been detected:
+ - More than 64 consecutive bits at the same value (0 or 1)
+ - More than 32 consecutive alternance of 0 and 1 (0101010101...01)
+ This interrupt source is cleared using RNG_ClearITPendingBit(RNG_IT_SEI)
+ function.
+
+ or
+ 3. In the case of a clock error : the PLL48CLK (RNG peripheral clock source)
+ was not correctly detected (fPLL48CLK< fHCLK/16).
+ This interrupt source is cleared using RNG_ClearITPendingBit(RNG_IT_CEI)
+ function.
+ @note In this case, User have to check that the clock controller is
+ correctly configured to provide the RNG clock.
+
+ Managing the RNG controller events :
+ ------------------------------------
+ The user should identify which mode will be used in his application to manage
+ the RNG controller events: Polling mode or Interrupt mode.
+
+ 1. In the Polling Mode it is advised to use the following functions:
+ - RNG_GetFlagStatus() : to check if flags events occur.
+ - RNG_ClearFlag() : to clear the flags events.
+
+ @note RNG_FLAG_DRDY can not be cleared by RNG_ClearFlag(). it is cleared only
+ by reading the Random number data.
+
+ 2. In the Interrupt Mode it is advised to use the following functions:
+ - RNG_ITConfig() : to enable or disable the interrupt source.
+ - RNG_GetITStatus() : to check if Interrupt occurs.
+ - RNG_ClearITPendingBit() : to clear the Interrupt pending Bit
+ (corresponding Flag).
+
+
+@endverbatim
+ * @{
+ */
+
+/**
+ * @brief Enables or disables the RNG interrupt.
+ * @note The RNG provides 3 interrupt sources,
+ * - Computed data is ready event (DRDY), and
+ * - Seed error Interrupt (SEI) and
+ * - Clock error Interrupt (CEI),
+ * all these interrupts sources are enabled by setting the IE bit in
+ * CR register. However, each interrupt have its specific status bit
+ * (see RNG_GetITStatus() function) and clear bit except the DRDY event
+ * (see RNG_ClearITPendingBit() function).
+ * @param NewState: new state of the RNG interrupt.
+ * This parameter can be: ENABLE or DISABLE.
+ * @retval None
+ */
+void RNG_ITConfig(FunctionalState NewState)
+{
+ /* Check the parameters */
+ assert_param(IS_FUNCTIONAL_STATE(NewState));
+
+ if (NewState != DISABLE)
+ {
+ /* Enable the RNG interrupt */
+ RNG->CR |= RNG_CR_IE;
+ }
+ else
+ {
+ /* Disable the RNG interrupt */
+ RNG->CR &= ~RNG_CR_IE;
+ }
+}
+
+/**
+ * @brief Checks whether the specified RNG flag is set or not.
+ * @param RNG_FLAG: specifies the RNG flag to check.
+ * This parameter can be one of the following values:
+ * @arg RNG_FLAG_DRDY: Data Ready flag.
+ * @arg RNG_FLAG_CECS: Clock Error Current flag.
+ * @arg RNG_FLAG_SECS: Seed Error Current flag.
+ * @retval The new state of RNG_FLAG (SET or RESET).
+ */
+FlagStatus RNG_GetFlagStatus(uint8_t RNG_FLAG)
+{
+ FlagStatus bitstatus = RESET;
+ /* Check the parameters */
+ assert_param(IS_RNG_GET_FLAG(RNG_FLAG));
+
+ /* Check the status of the specified RNG flag */
+ if ((RNG->SR & RNG_FLAG) != (uint8_t)RESET)
+ {
+ /* RNG_FLAG is set */
+ bitstatus = SET;
+ }
+ else
+ {
+ /* RNG_FLAG is reset */
+ bitstatus = RESET;
+ }
+ /* Return the RNG_FLAG status */
+ return bitstatus;
+}
+
+
+/**
+ * @brief Clears the RNG flags.
+ * @param RNG_FLAG: specifies the flag to clear.
+ * This parameter can be any combination of the following values:
+ * @arg RNG_FLAG_CECS: Clock Error Current flag.
+ * @arg RNG_FLAG_SECS: Seed Error Current flag.
+ * @note RNG_FLAG_DRDY can not be cleared by RNG_ClearFlag() function.
+ * This flag is cleared only by reading the Random number data (using
+ * RNG_GetRandomNumber() function).
+ * @retval None
+ */
+void RNG_ClearFlag(uint8_t RNG_FLAG)
+{
+ /* Check the parameters */
+ assert_param(IS_RNG_CLEAR_FLAG(RNG_FLAG));
+ /* Clear the selected RNG flags */
+ RNG->SR = ~(uint32_t)(((uint32_t)RNG_FLAG) << 4);
+}
+
+/**
+ * @brief Checks whether the specified RNG interrupt has occurred or not.
+ * @param RNG_IT: specifies the RNG interrupt source to check.
+ * This parameter can be one of the following values:
+ * @arg RNG_IT_CEI: Clock Error Interrupt.
+ * @arg RNG_IT_SEI: Seed Error Interrupt.
+ * @retval The new state of RNG_IT (SET or RESET).
+ */
+ITStatus RNG_GetITStatus(uint8_t RNG_IT)
+{
+ ITStatus bitstatus = RESET;
+ /* Check the parameters */
+ assert_param(IS_RNG_GET_IT(RNG_IT));
+
+ /* Check the status of the specified RNG interrupt */
+ if ((RNG->SR & RNG_IT) != (uint8_t)RESET)
+ {
+ /* RNG_IT is set */
+ bitstatus = SET;
+ }
+ else
+ {
+ /* RNG_IT is reset */
+ bitstatus = RESET;
+ }
+ /* Return the RNG_IT status */
+ return bitstatus;
+}
+
+
+/**
+ * @brief Clears the RNG interrupt pending bit(s).
+ * @param RNG_IT: specifies the RNG interrupt pending bit(s) to clear.
+ * This parameter can be any combination of the following values:
+ * @arg RNG_IT_CEI: Clock Error Interrupt.
+ * @arg RNG_IT_SEI: Seed Error Interrupt.
+ * @retval None
+ */
+void RNG_ClearITPendingBit(uint8_t RNG_IT)
+{
+ /* Check the parameters */
+ assert_param(IS_RNG_IT(RNG_IT));
+
+ /* Clear the selected RNG interrupt pending bit */
+ RNG->SR = (uint8_t)~RNG_IT;
+}
+/**
+ * @}
+ */
+
+/**
+ * @}
+ */
+
+/**
+ * @}
+ */
+
+
+/**
+ * @}
+ */
+
+
+/******************* (C) COPYRIGHT 2011 STMicroelectronics *****END OF FILE****/
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