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Anonymous committed 532512c Draft

bugfix and add libraries for i2c access

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src/platform/stm32f4/FWlib/inc/stm32f4xx_i2c.h

+/**
+  ******************************************************************************
+  * @file    stm32f4xx_i2c.h
+  * @author  MCD Application Team
+  * @version V1.0.2
+  * @date    05-March-2012
+  * @brief   This file contains all the functions prototypes for the I2C firmware 
+  *          library.
+  ******************************************************************************
+  * @attention
+  *
+  * <h2><center>&copy; COPYRIGHT 2012 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.
+  *
+  ******************************************************************************
+  */ 
+
+/* Define to prevent recursive inclusion -------------------------------------*/
+#ifndef __STM32F4xx_I2C_H
+#define __STM32F4xx_I2C_H
+
+#ifdef __cplusplus
+ extern "C" {
+#endif
+
+/* Includes ------------------------------------------------------------------*/
+#include "stm32f4xx.h"
+
+/** @addtogroup STM32F4xx_StdPeriph_Driver
+  * @{
+  */
+
+/** @addtogroup I2C
+  * @{
+  */
+
+/* Exported types ------------------------------------------------------------*/
+
+/** 
+  * @brief  I2C Init structure definition  
+  */
+
+typedef struct
+{
+  uint32_t I2C_ClockSpeed;          /*!< Specifies the clock frequency.
+                                         This parameter must be set to a value lower than 400kHz */
+
+  uint16_t I2C_Mode;                /*!< Specifies the I2C mode.
+                                         This parameter can be a value of @ref I2C_mode */
+
+  uint16_t I2C_DutyCycle;           /*!< Specifies the I2C fast mode duty cycle.
+                                         This parameter can be a value of @ref I2C_duty_cycle_in_fast_mode */
+
+  uint16_t I2C_OwnAddress1;         /*!< Specifies the first device own address.
+                                         This parameter can be a 7-bit or 10-bit address. */
+
+  uint16_t I2C_Ack;                 /*!< Enables or disables the acknowledgement.
+                                         This parameter can be a value of @ref I2C_acknowledgement */
+
+  uint16_t I2C_AcknowledgedAddress; /*!< Specifies if 7-bit or 10-bit address is acknowledged.
+                                         This parameter can be a value of @ref I2C_acknowledged_address */
+}I2C_InitTypeDef;
+
+/* Exported constants --------------------------------------------------------*/
+
+
+/** @defgroup I2C_Exported_Constants
+  * @{
+  */
+
+#define IS_I2C_ALL_PERIPH(PERIPH) (((PERIPH) == I2C1) || \
+                                   ((PERIPH) == I2C2) || \
+                                   ((PERIPH) == I2C3))
+/** @defgroup I2C_mode 
+  * @{
+  */
+
+#define I2C_Mode_I2C                    ((uint16_t)0x0000)
+#define I2C_Mode_SMBusDevice            ((uint16_t)0x0002)  
+#define I2C_Mode_SMBusHost              ((uint16_t)0x000A)
+#define IS_I2C_MODE(MODE) (((MODE) == I2C_Mode_I2C) || \
+                           ((MODE) == I2C_Mode_SMBusDevice) || \
+                           ((MODE) == I2C_Mode_SMBusHost))
+/**
+  * @}
+  */
+
+/** @defgroup I2C_duty_cycle_in_fast_mode 
+  * @{
+  */
+
+#define I2C_DutyCycle_16_9              ((uint16_t)0x4000) /*!< I2C fast mode Tlow/Thigh = 16/9 */
+#define I2C_DutyCycle_2                 ((uint16_t)0xBFFF) /*!< I2C fast mode Tlow/Thigh = 2 */
+#define IS_I2C_DUTY_CYCLE(CYCLE) (((CYCLE) == I2C_DutyCycle_16_9) || \
+                                  ((CYCLE) == I2C_DutyCycle_2))
+/**
+  * @}
+  */ 
+
+/** @defgroup I2C_acknowledgement
+  * @{
+  */
+
+#define I2C_Ack_Enable                  ((uint16_t)0x0400)
+#define I2C_Ack_Disable                 ((uint16_t)0x0000)
+#define IS_I2C_ACK_STATE(STATE) (((STATE) == I2C_Ack_Enable) || \
+                                 ((STATE) == I2C_Ack_Disable))
+/**
+  * @}
+  */
+
+/** @defgroup I2C_transfer_direction 
+  * @{
+  */
+
+#define  I2C_Direction_Transmitter      ((uint8_t)0x00)
+#define  I2C_Direction_Receiver         ((uint8_t)0x01)
+#define IS_I2C_DIRECTION(DIRECTION) (((DIRECTION) == I2C_Direction_Transmitter) || \
+                                     ((DIRECTION) == I2C_Direction_Receiver))
+/**
+  * @}
+  */
+
+/** @defgroup I2C_acknowledged_address 
+  * @{
+  */
+
+#define I2C_AcknowledgedAddress_7bit    ((uint16_t)0x4000)
+#define I2C_AcknowledgedAddress_10bit   ((uint16_t)0xC000)
+#define IS_I2C_ACKNOWLEDGE_ADDRESS(ADDRESS) (((ADDRESS) == I2C_AcknowledgedAddress_7bit) || \
+                                             ((ADDRESS) == I2C_AcknowledgedAddress_10bit))
+/**
+  * @}
+  */ 
+
+/** @defgroup I2C_registers 
+  * @{
+  */
+
+#define I2C_Register_CR1                ((uint8_t)0x00)
+#define I2C_Register_CR2                ((uint8_t)0x04)
+#define I2C_Register_OAR1               ((uint8_t)0x08)
+#define I2C_Register_OAR2               ((uint8_t)0x0C)
+#define I2C_Register_DR                 ((uint8_t)0x10)
+#define I2C_Register_SR1                ((uint8_t)0x14)
+#define I2C_Register_SR2                ((uint8_t)0x18)
+#define I2C_Register_CCR                ((uint8_t)0x1C)
+#define I2C_Register_TRISE              ((uint8_t)0x20)
+#define IS_I2C_REGISTER(REGISTER) (((REGISTER) == I2C_Register_CR1) || \
+                                   ((REGISTER) == I2C_Register_CR2) || \
+                                   ((REGISTER) == I2C_Register_OAR1) || \
+                                   ((REGISTER) == I2C_Register_OAR2) || \
+                                   ((REGISTER) == I2C_Register_DR) || \
+                                   ((REGISTER) == I2C_Register_SR1) || \
+                                   ((REGISTER) == I2C_Register_SR2) || \
+                                   ((REGISTER) == I2C_Register_CCR) || \
+                                   ((REGISTER) == I2C_Register_TRISE))
+/**
+  * @}
+  */
+
+/** @defgroup I2C_NACK_position 
+  * @{
+  */
+
+#define I2C_NACKPosition_Next           ((uint16_t)0x0800)
+#define I2C_NACKPosition_Current        ((uint16_t)0xF7FF)
+#define IS_I2C_NACK_POSITION(POSITION)  (((POSITION) == I2C_NACKPosition_Next) || \
+                                         ((POSITION) == I2C_NACKPosition_Current))
+/**
+  * @}
+  */ 
+
+/** @defgroup I2C_SMBus_alert_pin_level 
+  * @{
+  */
+
+#define I2C_SMBusAlert_Low              ((uint16_t)0x2000)
+#define I2C_SMBusAlert_High             ((uint16_t)0xDFFF)
+#define IS_I2C_SMBUS_ALERT(ALERT) (((ALERT) == I2C_SMBusAlert_Low) || \
+                                   ((ALERT) == I2C_SMBusAlert_High))
+/**
+  * @}
+  */
+
+/** @defgroup I2C_PEC_position 
+  * @{
+  */
+
+#define I2C_PECPosition_Next            ((uint16_t)0x0800)
+#define I2C_PECPosition_Current         ((uint16_t)0xF7FF)
+#define IS_I2C_PEC_POSITION(POSITION) (((POSITION) == I2C_PECPosition_Next) || \
+                                       ((POSITION) == I2C_PECPosition_Current))
+/**
+  * @}
+  */ 
+
+/** @defgroup I2C_interrupts_definition 
+  * @{
+  */
+
+#define I2C_IT_BUF                      ((uint16_t)0x0400)
+#define I2C_IT_EVT                      ((uint16_t)0x0200)
+#define I2C_IT_ERR                      ((uint16_t)0x0100)
+#define IS_I2C_CONFIG_IT(IT) ((((IT) & (uint16_t)0xF8FF) == 0x00) && ((IT) != 0x00))
+/**
+  * @}
+  */ 
+
+/** @defgroup I2C_interrupts_definition 
+  * @{
+  */
+
+#define I2C_IT_SMBALERT                 ((uint32_t)0x01008000)
+#define I2C_IT_TIMEOUT                  ((uint32_t)0x01004000)
+#define I2C_IT_PECERR                   ((uint32_t)0x01001000)
+#define I2C_IT_OVR                      ((uint32_t)0x01000800)
+#define I2C_IT_AF                       ((uint32_t)0x01000400)
+#define I2C_IT_ARLO                     ((uint32_t)0x01000200)
+#define I2C_IT_BERR                     ((uint32_t)0x01000100)
+#define I2C_IT_TXE                      ((uint32_t)0x06000080)
+#define I2C_IT_RXNE                     ((uint32_t)0x06000040)
+#define I2C_IT_STOPF                    ((uint32_t)0x02000010)
+#define I2C_IT_ADD10                    ((uint32_t)0x02000008)
+#define I2C_IT_BTF                      ((uint32_t)0x02000004)
+#define I2C_IT_ADDR                     ((uint32_t)0x02000002)
+#define I2C_IT_SB                       ((uint32_t)0x02000001)
+
+#define IS_I2C_CLEAR_IT(IT) ((((IT) & (uint16_t)0x20FF) == 0x00) && ((IT) != (uint16_t)0x00))
+
+#define IS_I2C_GET_IT(IT) (((IT) == I2C_IT_SMBALERT) || ((IT) == I2C_IT_TIMEOUT) || \
+                           ((IT) == I2C_IT_PECERR) || ((IT) == I2C_IT_OVR) || \
+                           ((IT) == I2C_IT_AF) || ((IT) == I2C_IT_ARLO) || \
+                           ((IT) == I2C_IT_BERR) || ((IT) == I2C_IT_TXE) || \
+                           ((IT) == I2C_IT_RXNE) || ((IT) == I2C_IT_STOPF) || \
+                           ((IT) == I2C_IT_ADD10) || ((IT) == I2C_IT_BTF) || \
+                           ((IT) == I2C_IT_ADDR) || ((IT) == I2C_IT_SB))
+/**
+  * @}
+  */
+
+/** @defgroup I2C_flags_definition 
+  * @{
+  */
+
+/** 
+  * @brief  SR2 register flags  
+  */
+
+#define I2C_FLAG_DUALF                  ((uint32_t)0x00800000)
+#define I2C_FLAG_SMBHOST                ((uint32_t)0x00400000)
+#define I2C_FLAG_SMBDEFAULT             ((uint32_t)0x00200000)
+#define I2C_FLAG_GENCALL                ((uint32_t)0x00100000)
+#define I2C_FLAG_TRA                    ((uint32_t)0x00040000)
+#define I2C_FLAG_BUSY                   ((uint32_t)0x00020000)
+#define I2C_FLAG_MSL                    ((uint32_t)0x00010000)
+
+/** 
+  * @brief  SR1 register flags  
+  */
+
+#define I2C_FLAG_SMBALERT               ((uint32_t)0x10008000)
+#define I2C_FLAG_TIMEOUT                ((uint32_t)0x10004000)
+#define I2C_FLAG_PECERR                 ((uint32_t)0x10001000)
+#define I2C_FLAG_OVR                    ((uint32_t)0x10000800)
+#define I2C_FLAG_AF                     ((uint32_t)0x10000400)
+#define I2C_FLAG_ARLO                   ((uint32_t)0x10000200)
+#define I2C_FLAG_BERR                   ((uint32_t)0x10000100)
+#define I2C_FLAG_TXE                    ((uint32_t)0x10000080)
+#define I2C_FLAG_RXNE                   ((uint32_t)0x10000040)
+#define I2C_FLAG_STOPF                  ((uint32_t)0x10000010)
+#define I2C_FLAG_ADD10                  ((uint32_t)0x10000008)
+#define I2C_FLAG_BTF                    ((uint32_t)0x10000004)
+#define I2C_FLAG_ADDR                   ((uint32_t)0x10000002)
+#define I2C_FLAG_SB                     ((uint32_t)0x10000001)
+
+#define IS_I2C_CLEAR_FLAG(FLAG) ((((FLAG) & (uint16_t)0x20FF) == 0x00) && ((FLAG) != (uint16_t)0x00))
+
+#define IS_I2C_GET_FLAG(FLAG) (((FLAG) == I2C_FLAG_DUALF) || ((FLAG) == I2C_FLAG_SMBHOST) || \
+                               ((FLAG) == I2C_FLAG_SMBDEFAULT) || ((FLAG) == I2C_FLAG_GENCALL) || \
+                               ((FLAG) == I2C_FLAG_TRA) || ((FLAG) == I2C_FLAG_BUSY) || \
+                               ((FLAG) == I2C_FLAG_MSL) || ((FLAG) == I2C_FLAG_SMBALERT) || \
+                               ((FLAG) == I2C_FLAG_TIMEOUT) || ((FLAG) == I2C_FLAG_PECERR) || \
+                               ((FLAG) == I2C_FLAG_OVR) || ((FLAG) == I2C_FLAG_AF) || \
+                               ((FLAG) == I2C_FLAG_ARLO) || ((FLAG) == I2C_FLAG_BERR) || \
+                               ((FLAG) == I2C_FLAG_TXE) || ((FLAG) == I2C_FLAG_RXNE) || \
+                               ((FLAG) == I2C_FLAG_STOPF) || ((FLAG) == I2C_FLAG_ADD10) || \
+                               ((FLAG) == I2C_FLAG_BTF) || ((FLAG) == I2C_FLAG_ADDR) || \
+                               ((FLAG) == I2C_FLAG_SB))
+/**
+  * @}
+  */
+
+/** @defgroup I2C_Events 
+  * @{
+  */
+
+/**
+ ===============================================================================
+               I2C Master Events (Events grouped in order of communication)
+ ===============================================================================
+ */
+
+/** 
+  * @brief  Communication start
+  * 
+  * After sending the START condition (I2C_GenerateSTART() function) the master 
+  * has to wait for this event. It means that the Start condition has been correctly 
+  * released on the I2C bus (the bus is free, no other devices is communicating).
+  * 
+  */
+/* --EV5 */
+#define  I2C_EVENT_MASTER_MODE_SELECT                      ((uint32_t)0x00030001)  /* BUSY, MSL and SB flag */
+
+/** 
+  * @brief  Address Acknowledge
+  * 
+  * After checking on EV5 (start condition correctly released on the bus), the 
+  * master sends the address of the slave(s) with which it will communicate 
+  * (I2C_Send7bitAddress() function, it also determines the direction of the communication: 
+  * Master transmitter or Receiver). Then the master has to wait that a slave acknowledges 
+  * his address. If an acknowledge is sent on the bus, one of the following events will 
+  * be set:
+  * 
+  *  1) In case of Master Receiver (7-bit addressing): the I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED 
+  *     event is set.
+  *  
+  *  2) In case of Master Transmitter (7-bit addressing): the I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED 
+  *     is set
+  *  
+  *  3) In case of 10-Bit addressing mode, the master (just after generating the START 
+  *  and checking on EV5) has to send the header of 10-bit addressing mode (I2C_SendData() 
+  *  function). Then master should wait on EV9. It means that the 10-bit addressing 
+  *  header has been correctly sent on the bus. Then master should send the second part of 
+  *  the 10-bit address (LSB) using the function I2C_Send7bitAddress(). Then master 
+  *  should wait for event EV6. 
+  *     
+  */
+
+/* --EV6 */
+#define  I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED        ((uint32_t)0x00070082)  /* BUSY, MSL, ADDR, TXE and TRA flags */
+#define  I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED           ((uint32_t)0x00030002)  /* BUSY, MSL and ADDR flags */
+/* --EV9 */
+#define  I2C_EVENT_MASTER_MODE_ADDRESS10                   ((uint32_t)0x00030008)  /* BUSY, MSL and ADD10 flags */
+
+/** 
+  * @brief Communication events
+  * 
+  * If a communication is established (START condition generated and slave address 
+  * acknowledged) then the master has to check on one of the following events for 
+  * communication procedures:
+  *  
+  * 1) Master Receiver mode: The master has to wait on the event EV7 then to read 
+  *    the data received from the slave (I2C_ReceiveData() function).
+  * 
+  * 2) Master Transmitter mode: The master has to send data (I2C_SendData() 
+  *    function) then to wait on event EV8 or EV8_2.
+  *    These two events are similar: 
+  *     - EV8 means that the data has been written in the data register and is 
+  *       being shifted out.
+  *     - EV8_2 means that the data has been physically shifted out and output 
+  *       on the bus.
+  *     In most cases, using EV8 is sufficient for the application.
+  *     Using EV8_2 leads to a slower communication but ensure more reliable test.
+  *     EV8_2 is also more suitable than EV8 for testing on the last data transmission 
+  *     (before Stop condition generation).
+  *     
+  *  @note In case the  user software does not guarantee that this event EV7 is 
+  *        managed before the current byte end of transfer, then user may check on EV7 
+  *        and BTF flag at the same time (ie. (I2C_EVENT_MASTER_BYTE_RECEIVED | I2C_FLAG_BTF)).
+  *        In this case the communication may be slower.
+  * 
+  */
+
+/* Master RECEIVER mode -----------------------------*/ 
+/* --EV7 */
+#define  I2C_EVENT_MASTER_BYTE_RECEIVED                    ((uint32_t)0x00030040)  /* BUSY, MSL and RXNE flags */
+
+/* Master TRANSMITTER mode --------------------------*/
+/* --EV8 */
+#define I2C_EVENT_MASTER_BYTE_TRANSMITTING                 ((uint32_t)0x00070080) /* TRA, BUSY, MSL, TXE flags */
+/* --EV8_2 */
+#define  I2C_EVENT_MASTER_BYTE_TRANSMITTED                 ((uint32_t)0x00070084)  /* TRA, BUSY, MSL, TXE and BTF flags */
+
+
+/**
+ ===============================================================================
+               I2C Slave Events (Events grouped in order of communication)
+ ===============================================================================
+ */
+
+
+/** 
+  * @brief  Communication start events
+  * 
+  * Wait on one of these events at the start of the communication. It means that 
+  * the I2C peripheral detected a Start condition on the bus (generated by master 
+  * device) followed by the peripheral address. The peripheral generates an ACK 
+  * condition on the bus (if the acknowledge feature is enabled through function 
+  * I2C_AcknowledgeConfig()) and the events listed above are set :
+  *  
+  * 1) In normal case (only one address managed by the slave), when the address 
+  *   sent by the master matches the own address of the peripheral (configured by 
+  *   I2C_OwnAddress1 field) the I2C_EVENT_SLAVE_XXX_ADDRESS_MATCHED event is set 
+  *   (where XXX could be TRANSMITTER or RECEIVER).
+  *    
+  * 2) In case the address sent by the master matches the second address of the 
+  *   peripheral (configured by the function I2C_OwnAddress2Config() and enabled 
+  *   by the function I2C_DualAddressCmd()) the events I2C_EVENT_SLAVE_XXX_SECONDADDRESS_MATCHED 
+  *   (where XXX could be TRANSMITTER or RECEIVER) are set.
+  *   
+  * 3) In case the address sent by the master is General Call (address 0x00) and 
+  *   if the General Call is enabled for the peripheral (using function I2C_GeneralCallCmd()) 
+  *   the following event is set I2C_EVENT_SLAVE_GENERALCALLADDRESS_MATCHED.   
+  * 
+  */
+
+/* --EV1  (all the events below are variants of EV1) */   
+/* 1) Case of One Single Address managed by the slave */
+#define  I2C_EVENT_SLAVE_RECEIVER_ADDRESS_MATCHED          ((uint32_t)0x00020002) /* BUSY and ADDR flags */
+#define  I2C_EVENT_SLAVE_TRANSMITTER_ADDRESS_MATCHED       ((uint32_t)0x00060082) /* TRA, BUSY, TXE and ADDR flags */
+
+/* 2) Case of Dual address managed by the slave */
+#define  I2C_EVENT_SLAVE_RECEIVER_SECONDADDRESS_MATCHED    ((uint32_t)0x00820000)  /* DUALF and BUSY flags */
+#define  I2C_EVENT_SLAVE_TRANSMITTER_SECONDADDRESS_MATCHED ((uint32_t)0x00860080)  /* DUALF, TRA, BUSY and TXE flags */
+
+/* 3) Case of General Call enabled for the slave */
+#define  I2C_EVENT_SLAVE_GENERALCALLADDRESS_MATCHED        ((uint32_t)0x00120000)  /* GENCALL and BUSY flags */
+
+/** 
+  * @brief  Communication events
+  * 
+  * Wait on one of these events when EV1 has already been checked and: 
+  * 
+  * - Slave RECEIVER mode:
+  *     - EV2: When the application is expecting a data byte to be received. 
+  *     - EV4: When the application is expecting the end of the communication: master 
+  *       sends a stop condition and data transmission is stopped.
+  *    
+  * - Slave Transmitter mode:
+  *    - EV3: When a byte has been transmitted by the slave and the application is expecting 
+  *      the end of the byte transmission. The two events I2C_EVENT_SLAVE_BYTE_TRANSMITTED and
+  *      I2C_EVENT_SLAVE_BYTE_TRANSMITTING are similar. The second one can optionally be 
+  *      used when the user software doesn't guarantee the EV3 is managed before the
+  *      current byte end of transfer.
+  *    - EV3_2: When the master sends a NACK in order to tell slave that data transmission 
+  *      shall end (before sending the STOP condition). In this case slave has to stop sending 
+  *      data bytes and expect a Stop condition on the bus.
+  *      
+  *  @note In case the  user software does not guarantee that the event EV2 is 
+  *        managed before the current byte end of transfer, then user may check on EV2 
+  *        and BTF flag at the same time (ie. (I2C_EVENT_SLAVE_BYTE_RECEIVED | I2C_FLAG_BTF)).
+  *        In this case the communication may be slower.
+  *
+  */
+
+/* Slave RECEIVER mode --------------------------*/ 
+/* --EV2 */
+#define  I2C_EVENT_SLAVE_BYTE_RECEIVED                     ((uint32_t)0x00020040)  /* BUSY and RXNE flags */
+/* --EV4  */
+#define  I2C_EVENT_SLAVE_STOP_DETECTED                     ((uint32_t)0x00000010)  /* STOPF flag */
+
+/* Slave TRANSMITTER mode -----------------------*/
+/* --EV3 */
+#define  I2C_EVENT_SLAVE_BYTE_TRANSMITTED                  ((uint32_t)0x00060084)  /* TRA, BUSY, TXE and BTF flags */
+#define  I2C_EVENT_SLAVE_BYTE_TRANSMITTING                 ((uint32_t)0x00060080)  /* TRA, BUSY and TXE flags */
+/* --EV3_2 */
+#define  I2C_EVENT_SLAVE_ACK_FAILURE                       ((uint32_t)0x00000400)  /* AF flag */
+
+/*
+ ===============================================================================
+                          End of Events Description
+ ===============================================================================
+ */
+
+#define IS_I2C_EVENT(EVENT) (((EVENT) == I2C_EVENT_SLAVE_TRANSMITTER_ADDRESS_MATCHED) || \
+                             ((EVENT) == I2C_EVENT_SLAVE_RECEIVER_ADDRESS_MATCHED) || \
+                             ((EVENT) == I2C_EVENT_SLAVE_TRANSMITTER_SECONDADDRESS_MATCHED) || \
+                             ((EVENT) == I2C_EVENT_SLAVE_RECEIVER_SECONDADDRESS_MATCHED) || \
+                             ((EVENT) == I2C_EVENT_SLAVE_GENERALCALLADDRESS_MATCHED) || \
+                             ((EVENT) == I2C_EVENT_SLAVE_BYTE_RECEIVED) || \
+                             ((EVENT) == (I2C_EVENT_SLAVE_BYTE_RECEIVED | I2C_FLAG_DUALF)) || \
+                             ((EVENT) == (I2C_EVENT_SLAVE_BYTE_RECEIVED | I2C_FLAG_GENCALL)) || \
+                             ((EVENT) == I2C_EVENT_SLAVE_BYTE_TRANSMITTED) || \
+                             ((EVENT) == (I2C_EVENT_SLAVE_BYTE_TRANSMITTED | I2C_FLAG_DUALF)) || \
+                             ((EVENT) == (I2C_EVENT_SLAVE_BYTE_TRANSMITTED | I2C_FLAG_GENCALL)) || \
+                             ((EVENT) == I2C_EVENT_SLAVE_STOP_DETECTED) || \
+                             ((EVENT) == I2C_EVENT_MASTER_MODE_SELECT) || \
+                             ((EVENT) == I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED) || \
+                             ((EVENT) == I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED) || \
+                             ((EVENT) == I2C_EVENT_MASTER_BYTE_RECEIVED) || \
+                             ((EVENT) == I2C_EVENT_MASTER_BYTE_TRANSMITTED) || \
+                             ((EVENT) == I2C_EVENT_MASTER_BYTE_TRANSMITTING) || \
+                             ((EVENT) == I2C_EVENT_MASTER_MODE_ADDRESS10) || \
+                             ((EVENT) == I2C_EVENT_SLAVE_ACK_FAILURE))
+/**
+  * @}
+  */
+
+/** @defgroup I2C_own_address1 
+  * @{
+  */
+
+#define IS_I2C_OWN_ADDRESS1(ADDRESS1) ((ADDRESS1) <= 0x3FF)
+/**
+  * @}
+  */
+
+/** @defgroup I2C_clock_speed 
+  * @{
+  */
+
+#define IS_I2C_CLOCK_SPEED(SPEED) (((SPEED) >= 0x1) && ((SPEED) <= 400000))
+/**
+  * @}
+  */
+
+/**
+  * @}
+  */
+
+/* Exported macro ------------------------------------------------------------*/
+/* Exported functions --------------------------------------------------------*/ 
+
+/*  Function used to set the I2C configuration to the default reset state *****/
+void I2C_DeInit(I2C_TypeDef* I2Cx);
+
+/* Initialization and Configuration functions *********************************/
+void I2C_Init(I2C_TypeDef* I2Cx, I2C_InitTypeDef* I2C_InitStruct);
+void I2C_StructInit(I2C_InitTypeDef* I2C_InitStruct);
+void I2C_Cmd(I2C_TypeDef* I2Cx, FunctionalState NewState);
+void I2C_GenerateSTART(I2C_TypeDef* I2Cx, FunctionalState NewState);
+void I2C_GenerateSTOP(I2C_TypeDef* I2Cx, FunctionalState NewState);
+void I2C_Send7bitAddress(I2C_TypeDef* I2Cx, uint8_t Address, uint8_t I2C_Direction);
+void I2C_AcknowledgeConfig(I2C_TypeDef* I2Cx, FunctionalState NewState);
+void I2C_OwnAddress2Config(I2C_TypeDef* I2Cx, uint8_t Address);
+void I2C_DualAddressCmd(I2C_TypeDef* I2Cx, FunctionalState NewState);
+void I2C_GeneralCallCmd(I2C_TypeDef* I2Cx, FunctionalState NewState);
+void I2C_SoftwareResetCmd(I2C_TypeDef* I2Cx, FunctionalState NewState);
+void I2C_StretchClockCmd(I2C_TypeDef* I2Cx, FunctionalState NewState);
+void I2C_FastModeDutyCycleConfig(I2C_TypeDef* I2Cx, uint16_t I2C_DutyCycle);
+void I2C_NACKPositionConfig(I2C_TypeDef* I2Cx, uint16_t I2C_NACKPosition);
+void I2C_SMBusAlertConfig(I2C_TypeDef* I2Cx, uint16_t I2C_SMBusAlert);
+void I2C_ARPCmd(I2C_TypeDef* I2Cx, FunctionalState NewState);
+
+/* Data transfers functions ***************************************************/ 
+void I2C_SendData(I2C_TypeDef* I2Cx, uint8_t Data);
+uint8_t I2C_ReceiveData(I2C_TypeDef* I2Cx);
+
+/* PEC management functions ***************************************************/ 
+void I2C_TransmitPEC(I2C_TypeDef* I2Cx, FunctionalState NewState);
+void I2C_PECPositionConfig(I2C_TypeDef* I2Cx, uint16_t I2C_PECPosition);
+void I2C_CalculatePEC(I2C_TypeDef* I2Cx, FunctionalState NewState);
+uint8_t I2C_GetPEC(I2C_TypeDef* I2Cx);
+
+/* DMA transfers management functions *****************************************/
+void I2C_DMACmd(I2C_TypeDef* I2Cx, FunctionalState NewState);
+void I2C_DMALastTransferCmd(I2C_TypeDef* I2Cx, FunctionalState NewState);
+
+/* Interrupts, events and flags management functions **************************/
+uint16_t I2C_ReadRegister(I2C_TypeDef* I2Cx, uint8_t I2C_Register);
+void I2C_ITConfig(I2C_TypeDef* I2Cx, uint16_t I2C_IT, FunctionalState NewState);
+
+/* 
+ ===============================================================================
+                          I2C State Monitoring Functions
+ ===============================================================================
+  This I2C driver provides three different ways for I2C state monitoring
+  depending on the application requirements and constraints:
+         
+   
+     1. Basic state monitoring (Using I2C_CheckEvent() function)
+     -----------------------------------------------------------
+        It compares the status registers (SR1 and SR2) content to a given event
+        (can be the combination of one or more flags).
+        It returns SUCCESS if the current status includes the given flags 
+        and returns ERROR if one or more flags are missing in the current status.
+
+          - When to use
+             - This function is suitable for most applications as well as for startup 
+               activity since the events are fully described in the product reference 
+               manual (RM0090).
+             - It is also suitable for users who need to define their own events.
+
+          - Limitations
+             - If an error occurs (ie. error flags are set besides to the monitored 
+               flags), the I2C_CheckEvent() function may return SUCCESS despite 
+               the communication hold or corrupted real state. 
+               In this case, it is advised to use error interrupts to monitor 
+               the error events and handle them in the interrupt IRQ handler.
+         
+     Note 
+         For error management, it is advised to use the following functions:
+           - I2C_ITConfig() to configure and enable the error interrupts (I2C_IT_ERR).
+           - I2Cx_ER_IRQHandler() which is called when the error interrupt occurs.
+             Where x is the peripheral instance (I2C1, I2C2 ...)
+           - I2C_GetFlagStatus() or I2C_GetITStatus()  to be called into the 
+             I2Cx_ER_IRQHandler() function in order to determine which error occurred.
+           - I2C_ClearFlag() or I2C_ClearITPendingBit() and/or I2C_SoftwareResetCmd() 
+             and/or I2C_GenerateStop() in order to clear the error flag and source 
+             and return to correct  communication status.
+             
+ 
+     2. Advanced state monitoring (Using the function I2C_GetLastEvent())
+     -------------------------------------------------------------------- 
+        Using the function I2C_GetLastEvent() which returns the image of both status 
+        registers in a single word (uint32_t) (Status Register 2 value is shifted left 
+        by 16 bits and concatenated to Status Register 1).
+
+          - When to use
+             - This function is suitable for the same applications above but it 
+               allows to overcome the mentioned limitation of I2C_GetFlagStatus() 
+               function.
+             - The returned value could be compared to events already defined in 
+               this file or to custom values defined by user.
+               This function is suitable when multiple flags are monitored at the 
+               same time.
+             - At the opposite of I2C_CheckEvent() function, this function allows 
+               user to choose when an event is accepted (when all events flags are 
+               set and no other flags are set or just when the needed flags are set 
+               like I2C_CheckEvent() function.
+
+          - Limitations
+             - User may need to define his own events.
+             - Same remark concerning the error management is applicable for this 
+               function if user decides to check only regular communication flags 
+               (and ignores error flags).
+      
+ 
+     3. Flag-based state monitoring (Using the function I2C_GetFlagStatus())
+     -----------------------------------------------------------------------
+     
+      Using the function I2C_GetFlagStatus() which simply returns the status of 
+      one single flag (ie. I2C_FLAG_RXNE ...). 
+
+          - When to use
+             - This function could be used for specific applications or in debug 
+               phase.
+             - It is suitable when only one flag checking is needed (most I2C 
+               events are monitored through multiple flags).
+          - Limitations: 
+             - When calling this function, the Status register is accessed. 
+               Some flags are cleared when the status register is accessed. 
+               So checking the status of one Flag, may clear other ones.
+             - Function may need to be called twice or more in order to monitor 
+               one single event.           
+ */
+
+/*
+ ===============================================================================
+                          1. Basic state monitoring
+ ===============================================================================
+ */
+ErrorStatus I2C_CheckEvent(I2C_TypeDef* I2Cx, uint32_t I2C_EVENT);
+/*
+ ===============================================================================
+                          2. Advanced state monitoring
+ ===============================================================================
+ */
+uint32_t I2C_GetLastEvent(I2C_TypeDef* I2Cx);
+/*
+ ===============================================================================
+                          3. Flag-based state monitoring
+ ===============================================================================
+ */
+FlagStatus I2C_GetFlagStatus(I2C_TypeDef* I2Cx, uint32_t I2C_FLAG);
+
+
+void I2C_ClearFlag(I2C_TypeDef* I2Cx, uint32_t I2C_FLAG);
+ITStatus I2C_GetITStatus(I2C_TypeDef* I2Cx, uint32_t I2C_IT);
+void I2C_ClearITPendingBit(I2C_TypeDef* I2Cx, uint32_t I2C_IT);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /*__STM32F4xx_I2C_H */
+
+/**
+  * @}
+  */ 
+
+/**
+  * @}
+  */ 
+
+/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

src/platform/stm32f4/FWlib/src/stm32f4xx_i2c.c

+/**
+  ******************************************************************************
+  * @file    stm32f4xx_i2c.c
+  * @author  MCD Application Team
+  * @version V1.0.2
+  * @date    05-March-2012
+  * @brief   This file provides firmware functions to manage the following 
+  *          functionalities of the Inter-integrated circuit (I2C)
+  *           - Initialization and Configuration
+  *           - Data transfers
+  *           - PEC management
+  *           - DMA transfers management
+  *           - Interrupts, events and flags management 
+  *           
+  *  @verbatim
+  *    
+  *          ===================================================================
+  *                                 How to use this driver
+  *          ===================================================================
+  *          1. Enable peripheral clock using RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2Cx, ENABLE)
+  *             function for I2C1, I2C2 or I2C3.
+  *
+  *          2. Enable SDA, SCL  and SMBA (when used) GPIO clocks using 
+  *             RCC_AHBPeriphClockCmd() function. 
+  *
+  *          3. Peripherals alternate function: 
+  *                 - Connect the pin to the desired peripherals' Alternate 
+  *                   Function (AF) using GPIO_PinAFConfig() function
+  *                 - Configure the desired pin in alternate function by:
+  *                   GPIO_InitStruct->GPIO_Mode = GPIO_Mode_AF
+  *                 - Select the type, pull-up/pull-down and output speed via 
+  *                   GPIO_PuPd, GPIO_OType and GPIO_Speed members
+  *                 - Call GPIO_Init() function
+  *                 Recommended configuration is Push-Pull, Pull-up, Open-Drain.
+  *                 Add an external pull up if necessary (typically 4.7 KOhm).      
+  *        
+  *          4. Program the Mode, duty cycle , Own address, Ack, Speed and Acknowledged
+  *             Address using the I2C_Init() function.
+  *
+  *          5. Optionally you can enable/configure the following parameters without
+  *             re-initialization (i.e there is no need to call again I2C_Init() function):
+  *              - Enable the acknowledge feature using I2C_AcknowledgeConfig() function
+  *              - Enable the dual addressing mode using I2C_DualAddressCmd() function
+  *              - Enable the general call using the I2C_GeneralCallCmd() function
+  *              - Enable the clock stretching using I2C_StretchClockCmd() function
+  *              - Enable the fast mode duty cycle using the I2C_FastModeDutyCycleConfig()
+  *                function.
+  *              - Configure the NACK position for Master Receiver mode in case of 
+  *                2 bytes reception using the function I2C_NACKPositionConfig().  
+  *              - Enable the PEC Calculation using I2C_CalculatePEC() function
+  *              - For SMBus Mode: 
+  *                   - Enable the Address Resolution Protocol (ARP) using I2C_ARPCmd() function
+  *                   - Configure the SMBusAlert pin using I2C_SMBusAlertConfig() function
+  *
+  *          6. Enable the NVIC and the corresponding interrupt using the function 
+  *             I2C_ITConfig() if you need to use interrupt mode. 
+  *
+  *          7. When using the DMA mode 
+  *                   - Configure the DMA using DMA_Init() function
+  *                   - Active the needed channel Request using I2C_DMACmd() or
+  *                     I2C_DMALastTransferCmd() function.
+  *              @note When using DMA mode, I2C interrupts may be used at the same time to
+  *                    control the communication flow (Start/Stop/Ack... events and errors).
+  * 
+  *          8. Enable the I2C using the I2C_Cmd() function.
+  * 
+  *          9. Enable the DMA using the DMA_Cmd() function when using DMA mode in the 
+  *             transfers. 
+  *
+  *  @endverbatim
+  *  
+  ******************************************************************************
+  * @attention
+  *
+  * <h2><center>&copy; COPYRIGHT 2012 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 "stm32f4xx_i2c.h"
+#include "stm32f4xx_rcc.h"
+
+/** @addtogroup STM32F4xx_StdPeriph_Driver
+  * @{
+  */
+
+/** @defgroup I2C 
+  * @brief I2C driver modules
+  * @{
+  */ 
+
+/* Private typedef -----------------------------------------------------------*/
+/* Private define ------------------------------------------------------------*/
+
+#define CR1_CLEAR_MASK    ((uint16_t)0xFBF5)      /*<! I2C registers Masks */
+#define FLAG_MASK         ((uint32_t)0x00FFFFFF)  /*<! I2C FLAG mask */
+#define ITEN_MASK         ((uint32_t)0x07000000)  /*<! I2C Interrupt Enable mask */
+
+/* Private macro -------------------------------------------------------------*/
+/* Private variables ---------------------------------------------------------*/
+/* Private function prototypes -----------------------------------------------*/
+/* Private functions ---------------------------------------------------------*/
+
+/** @defgroup I2C_Private_Functions
+  * @{
+  */
+
+/** @defgroup I2C_Group1 Initialization and Configuration functions
+ *  @brief   Initialization and Configuration functions 
+ *
+@verbatim   
+ ===============================================================================
+                   Initialization and Configuration functions
+ ===============================================================================  
+
+@endverbatim
+  * @{
+  */
+
+/**
+  * @brief  Deinitialize the I2Cx peripheral registers to their default reset values.
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @retval None
+  */
+void I2C_DeInit(I2C_TypeDef* I2Cx)
+{
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+
+  if (I2Cx == I2C1)
+  {
+    /* Enable I2C1 reset state */
+    RCC_APB1PeriphResetCmd(RCC_APB1Periph_I2C1, ENABLE);
+    /* Release I2C1 from reset state */
+    RCC_APB1PeriphResetCmd(RCC_APB1Periph_I2C1, DISABLE);    
+  }
+  else if (I2Cx == I2C2)
+  {
+    /* Enable I2C2 reset state */
+    RCC_APB1PeriphResetCmd(RCC_APB1Periph_I2C2, ENABLE);
+    /* Release I2C2 from reset state */
+    RCC_APB1PeriphResetCmd(RCC_APB1Periph_I2C2, DISABLE);      
+  }
+  else 
+  {
+    if (I2Cx == I2C3)
+    {
+      /* Enable I2C3 reset state */
+      RCC_APB1PeriphResetCmd(RCC_APB1Periph_I2C3, ENABLE);
+      /* Release I2C3 from reset state */
+      RCC_APB1PeriphResetCmd(RCC_APB1Periph_I2C3, DISABLE);     
+    }
+  }
+}
+
+/**
+  * @brief  Initializes the I2Cx peripheral according to the specified 
+  *         parameters in the I2C_InitStruct.
+  *           
+  * @note   To use the I2C at 400 KHz (in fast mode), the PCLK1 frequency 
+  *         (I2C peripheral input clock) must be a multiple of 10 MHz.  
+  *           
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @param  I2C_InitStruct: pointer to a I2C_InitTypeDef structure that contains 
+  *         the configuration information for the specified I2C peripheral.
+  * @retval None
+  */
+void I2C_Init(I2C_TypeDef* I2Cx, I2C_InitTypeDef* I2C_InitStruct)
+{
+  uint16_t tmpreg = 0, freqrange = 0;
+  uint16_t result = 0x04;
+  uint32_t pclk1 = 8000000;
+  RCC_ClocksTypeDef  rcc_clocks;
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+  assert_param(IS_I2C_CLOCK_SPEED(I2C_InitStruct->I2C_ClockSpeed));
+  assert_param(IS_I2C_MODE(I2C_InitStruct->I2C_Mode));
+  assert_param(IS_I2C_DUTY_CYCLE(I2C_InitStruct->I2C_DutyCycle));
+  assert_param(IS_I2C_OWN_ADDRESS1(I2C_InitStruct->I2C_OwnAddress1));
+  assert_param(IS_I2C_ACK_STATE(I2C_InitStruct->I2C_Ack));
+  assert_param(IS_I2C_ACKNOWLEDGE_ADDRESS(I2C_InitStruct->I2C_AcknowledgedAddress));
+
+/*---------------------------- I2Cx CR2 Configuration ------------------------*/
+  /* Get the I2Cx CR2 value */
+  tmpreg = I2Cx->CR2;
+  /* Clear frequency FREQ[5:0] bits */
+  tmpreg &= (uint16_t)~((uint16_t)I2C_CR2_FREQ);
+  /* Get pclk1 frequency value */
+  RCC_GetClocksFreq(&rcc_clocks);
+  pclk1 = rcc_clocks.PCLK1_Frequency;
+  /* Set frequency bits depending on pclk1 value */
+  freqrange = (uint16_t)(pclk1 / 1000000);
+  tmpreg |= freqrange;
+  /* Write to I2Cx CR2 */
+  I2Cx->CR2 = tmpreg;
+
+/*---------------------------- I2Cx CCR Configuration ------------------------*/
+  /* Disable the selected I2C peripheral to configure TRISE */
+  I2Cx->CR1 &= (uint16_t)~((uint16_t)I2C_CR1_PE);
+  /* Reset tmpreg value */
+  /* Clear F/S, DUTY and CCR[11:0] bits */
+  tmpreg = 0;
+
+  /* Configure speed in standard mode */
+  if (I2C_InitStruct->I2C_ClockSpeed <= 100000)
+  {
+    /* Standard mode speed calculate */
+    result = (uint16_t)(pclk1 / (I2C_InitStruct->I2C_ClockSpeed << 1));
+    /* Test if CCR value is under 0x4*/
+    if (result < 0x04)
+    {
+      /* Set minimum allowed value */
+      result = 0x04;  
+    }
+    /* Set speed value for standard mode */
+    tmpreg |= result;	  
+    /* Set Maximum Rise Time for standard mode */
+    I2Cx->TRISE = freqrange + 1; 
+  }
+  /* Configure speed in fast mode */
+  /* To use the I2C at 400 KHz (in fast mode), the PCLK1 frequency (I2C peripheral
+     input clock) must be a multiple of 10 MHz */
+  else /*(I2C_InitStruct->I2C_ClockSpeed <= 400000)*/
+  {
+    if (I2C_InitStruct->I2C_DutyCycle == I2C_DutyCycle_2)
+    {
+      /* Fast mode speed calculate: Tlow/Thigh = 2 */
+      result = (uint16_t)(pclk1 / (I2C_InitStruct->I2C_ClockSpeed * 3));
+    }
+    else /*I2C_InitStruct->I2C_DutyCycle == I2C_DutyCycle_16_9*/
+    {
+      /* Fast mode speed calculate: Tlow/Thigh = 16/9 */
+      result = (uint16_t)(pclk1 / (I2C_InitStruct->I2C_ClockSpeed * 25));
+      /* Set DUTY bit */
+      result |= I2C_DutyCycle_16_9;
+    }
+
+    /* Test if CCR value is under 0x1*/
+    if ((result & I2C_CCR_CCR) == 0)
+    {
+      /* Set minimum allowed value */
+      result |= (uint16_t)0x0001;  
+    }
+    /* Set speed value and set F/S bit for fast mode */
+    tmpreg |= (uint16_t)(result | I2C_CCR_FS);
+    /* Set Maximum Rise Time for fast mode */
+    I2Cx->TRISE = (uint16_t)(((freqrange * (uint16_t)300) / (uint16_t)1000) + (uint16_t)1);  
+  }
+
+  /* Write to I2Cx CCR */
+  I2Cx->CCR = tmpreg;
+  /* Enable the selected I2C peripheral */
+  I2Cx->CR1 |= I2C_CR1_PE;
+
+/*---------------------------- I2Cx CR1 Configuration ------------------------*/
+  /* Get the I2Cx CR1 value */
+  tmpreg = I2Cx->CR1;
+  /* Clear ACK, SMBTYPE and  SMBUS bits */
+  tmpreg &= CR1_CLEAR_MASK;
+  /* Configure I2Cx: mode and acknowledgement */
+  /* Set SMBTYPE and SMBUS bits according to I2C_Mode value */
+  /* Set ACK bit according to I2C_Ack value */
+  tmpreg |= (uint16_t)((uint32_t)I2C_InitStruct->I2C_Mode | I2C_InitStruct->I2C_Ack);
+  /* Write to I2Cx CR1 */
+  I2Cx->CR1 = tmpreg;
+
+/*---------------------------- I2Cx OAR1 Configuration -----------------------*/
+  /* Set I2Cx Own Address1 and acknowledged address */
+  I2Cx->OAR1 = (I2C_InitStruct->I2C_AcknowledgedAddress | I2C_InitStruct->I2C_OwnAddress1);
+}
+
+/**
+  * @brief  Fills each I2C_InitStruct member with its default value.
+  * @param  I2C_InitStruct: pointer to an I2C_InitTypeDef structure which will be initialized.
+  * @retval None
+  */
+void I2C_StructInit(I2C_InitTypeDef* I2C_InitStruct)
+{
+/*---------------- Reset I2C init structure parameters values ----------------*/
+  /* initialize the I2C_ClockSpeed member */
+  I2C_InitStruct->I2C_ClockSpeed = 5000;
+  /* Initialize the I2C_Mode member */
+  I2C_InitStruct->I2C_Mode = I2C_Mode_I2C;
+  /* Initialize the I2C_DutyCycle member */
+  I2C_InitStruct->I2C_DutyCycle = I2C_DutyCycle_2;
+  /* Initialize the I2C_OwnAddress1 member */
+  I2C_InitStruct->I2C_OwnAddress1 = 0;
+  /* Initialize the I2C_Ack member */
+  I2C_InitStruct->I2C_Ack = I2C_Ack_Disable;
+  /* Initialize the I2C_AcknowledgedAddress member */
+  I2C_InitStruct->I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
+}
+
+/**
+  * @brief  Enables or disables the specified I2C peripheral.
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @param  NewState: new state of the I2Cx peripheral. 
+  *          This parameter can be: ENABLE or DISABLE.
+  * @retval None
+  */
+void I2C_Cmd(I2C_TypeDef* I2Cx, FunctionalState NewState)
+{
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+  assert_param(IS_FUNCTIONAL_STATE(NewState));
+  if (NewState != DISABLE)
+  {
+    /* Enable the selected I2C peripheral */
+    I2Cx->CR1 |= I2C_CR1_PE;
+  }
+  else
+  {
+    /* Disable the selected I2C peripheral */
+    I2Cx->CR1 &= (uint16_t)~((uint16_t)I2C_CR1_PE);
+  }
+}
+
+/**
+  * @brief  Generates I2Cx communication START condition.
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @param  NewState: new state of the I2C START condition generation.
+  *          This parameter can be: ENABLE or DISABLE.
+  * @retval None.
+  */
+void I2C_GenerateSTART(I2C_TypeDef* I2Cx, FunctionalState NewState)
+{
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+  assert_param(IS_FUNCTIONAL_STATE(NewState));
+  if (NewState != DISABLE)
+  {
+    /* Generate a START condition */
+    I2Cx->CR1 |= I2C_CR1_START;
+  }
+  else
+  {
+    /* Disable the START condition generation */
+    I2Cx->CR1 &= (uint16_t)~((uint16_t)I2C_CR1_START);
+  }
+}
+
+/**
+  * @brief  Generates I2Cx communication STOP condition.
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @param  NewState: new state of the I2C STOP condition generation.
+  *          This parameter can be: ENABLE or DISABLE.
+  * @retval None.
+  */
+void I2C_GenerateSTOP(I2C_TypeDef* I2Cx, FunctionalState NewState)
+{
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+  assert_param(IS_FUNCTIONAL_STATE(NewState));
+  if (NewState != DISABLE)
+  {
+    /* Generate a STOP condition */
+    I2Cx->CR1 |= I2C_CR1_STOP;
+  }
+  else
+  {
+    /* Disable the STOP condition generation */
+    I2Cx->CR1 &= (uint16_t)~((uint16_t)I2C_CR1_STOP);
+  }
+}
+
+/**
+  * @brief  Transmits the address byte to select the slave device.
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @param  Address: specifies the slave address which will be transmitted
+  * @param  I2C_Direction: specifies whether the I2C device will be a Transmitter
+  *         or a Receiver. 
+  *          This parameter can be one of the following values
+  *            @arg I2C_Direction_Transmitter: Transmitter mode
+  *            @arg I2C_Direction_Receiver: Receiver mode
+  * @retval None.
+  */
+void I2C_Send7bitAddress(I2C_TypeDef* I2Cx, uint8_t Address, uint8_t I2C_Direction)
+{
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+  assert_param(IS_I2C_DIRECTION(I2C_Direction));
+  /* Test on the direction to set/reset the read/write bit */
+  if (I2C_Direction != I2C_Direction_Transmitter)
+  {
+    /* Set the address bit0 for read */
+    Address |= I2C_OAR1_ADD0;
+  }
+  else
+  {
+    /* Reset the address bit0 for write */
+    Address &= (uint8_t)~((uint8_t)I2C_OAR1_ADD0);
+  }
+  /* Send the address */
+  I2Cx->DR = Address;
+}
+
+/**
+  * @brief  Enables or disables the specified I2C acknowledge feature.
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @param  NewState: new state of the I2C Acknowledgement.
+  *          This parameter can be: ENABLE or DISABLE.
+  * @retval None.
+  */
+void I2C_AcknowledgeConfig(I2C_TypeDef* I2Cx, FunctionalState NewState)
+{
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+  assert_param(IS_FUNCTIONAL_STATE(NewState));
+  if (NewState != DISABLE)
+  {
+    /* Enable the acknowledgement */
+    I2Cx->CR1 |= I2C_CR1_ACK;
+  }
+  else
+  {
+    /* Disable the acknowledgement */
+    I2Cx->CR1 &= (uint16_t)~((uint16_t)I2C_CR1_ACK);
+  }
+}
+
+/**
+  * @brief  Configures the specified I2C own address2.
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @param  Address: specifies the 7bit I2C own address2.
+  * @retval None.
+  */
+void I2C_OwnAddress2Config(I2C_TypeDef* I2Cx, uint8_t Address)
+{
+  uint16_t tmpreg = 0;
+
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+
+  /* Get the old register value */
+  tmpreg = I2Cx->OAR2;
+
+  /* Reset I2Cx Own address2 bit [7:1] */
+  tmpreg &= (uint16_t)~((uint16_t)I2C_OAR2_ADD2);
+
+  /* Set I2Cx Own address2 */
+  tmpreg |= (uint16_t)((uint16_t)Address & (uint16_t)0x00FE);
+
+  /* Store the new register value */
+  I2Cx->OAR2 = tmpreg;
+}
+
+/**
+  * @brief  Enables or disables the specified I2C dual addressing mode.
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @param  NewState: new state of the I2C dual addressing mode.
+  *          This parameter can be: ENABLE or DISABLE.
+  * @retval None
+  */
+void I2C_DualAddressCmd(I2C_TypeDef* I2Cx, FunctionalState NewState)
+{
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+  assert_param(IS_FUNCTIONAL_STATE(NewState));
+  if (NewState != DISABLE)
+  {
+    /* Enable dual addressing mode */
+    I2Cx->OAR2 |= I2C_OAR2_ENDUAL;
+  }
+  else
+  {
+    /* Disable dual addressing mode */
+    I2Cx->OAR2 &= (uint16_t)~((uint16_t)I2C_OAR2_ENDUAL);
+  }
+}
+
+/**
+  * @brief  Enables or disables the specified I2C general call feature.
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @param  NewState: new state of the I2C General call.
+  *          This parameter can be: ENABLE or DISABLE.
+  * @retval None
+  */
+void I2C_GeneralCallCmd(I2C_TypeDef* I2Cx, FunctionalState NewState)
+{
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+  assert_param(IS_FUNCTIONAL_STATE(NewState));
+  if (NewState != DISABLE)
+  {
+    /* Enable generall call */
+    I2Cx->CR1 |= I2C_CR1_ENGC;
+  }
+  else
+  {
+    /* Disable generall call */
+    I2Cx->CR1 &= (uint16_t)~((uint16_t)I2C_CR1_ENGC);
+  }
+}
+
+/**
+  * @brief  Enables or disables the specified I2C software reset.
+  * @note   When software reset is enabled, the I2C IOs are released (this can
+  *         be useful to recover from bus errors).  
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @param  NewState: new state of the I2C software reset.
+  *          This parameter can be: ENABLE or DISABLE.
+  * @retval None
+  */
+void I2C_SoftwareResetCmd(I2C_TypeDef* I2Cx, FunctionalState NewState)
+{
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+  assert_param(IS_FUNCTIONAL_STATE(NewState));
+  if (NewState != DISABLE)
+  {
+    /* Peripheral under reset */
+    I2Cx->CR1 |= I2C_CR1_SWRST;
+  }
+  else
+  {
+    /* Peripheral not under reset */
+    I2Cx->CR1 &= (uint16_t)~((uint16_t)I2C_CR1_SWRST);
+  }
+}
+
+/**
+  * @brief  Enables or disables the specified I2C Clock stretching.
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @param  NewState: new state of the I2Cx Clock stretching.
+  *          This parameter can be: ENABLE or DISABLE.
+  * @retval None
+  */
+void I2C_StretchClockCmd(I2C_TypeDef* I2Cx, FunctionalState NewState)
+{
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+  assert_param(IS_FUNCTIONAL_STATE(NewState));
+  if (NewState == DISABLE)
+  {
+    /* Enable the selected I2C Clock stretching */
+    I2Cx->CR1 |= I2C_CR1_NOSTRETCH;
+  }
+  else
+  {
+    /* Disable the selected I2C Clock stretching */
+    I2Cx->CR1 &= (uint16_t)~((uint16_t)I2C_CR1_NOSTRETCH);
+  }
+}
+
+/**
+  * @brief  Selects the specified I2C fast mode duty cycle.
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @param  I2C_DutyCycle: specifies the fast mode duty cycle.
+  *          This parameter can be one of the following values:
+  *            @arg I2C_DutyCycle_2: I2C fast mode Tlow/Thigh = 2
+  *            @arg I2C_DutyCycle_16_9: I2C fast mode Tlow/Thigh = 16/9
+  * @retval None
+  */
+void I2C_FastModeDutyCycleConfig(I2C_TypeDef* I2Cx, uint16_t I2C_DutyCycle)
+{
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+  assert_param(IS_I2C_DUTY_CYCLE(I2C_DutyCycle));
+  if (I2C_DutyCycle != I2C_DutyCycle_16_9)
+  {
+    /* I2C fast mode Tlow/Thigh=2 */
+    I2Cx->CCR &= I2C_DutyCycle_2;
+  }
+  else
+  {
+    /* I2C fast mode Tlow/Thigh=16/9 */
+    I2Cx->CCR |= I2C_DutyCycle_16_9;
+  }
+}
+
+/**
+  * @brief  Selects the specified I2C NACK position in master receiver mode.
+  * @note   This function is useful in I2C Master Receiver mode when the number
+  *         of data to be received is equal to 2. In this case, this function 
+  *         should be called (with parameter I2C_NACKPosition_Next) before data 
+  *         reception starts,as described in the 2-byte reception procedure 
+  *         recommended in Reference Manual in Section: Master receiver.                
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @param  I2C_NACKPosition: specifies the NACK position. 
+  *          This parameter can be one of the following values:
+  *            @arg I2C_NACKPosition_Next: indicates that the next byte will be the last
+  *                                        received byte.  
+  *            @arg I2C_NACKPosition_Current: indicates that current byte is the last 
+  *                                           received byte.
+  *            
+  * @note    This function configures the same bit (POS) as I2C_PECPositionConfig() 
+  *          but is intended to be used in I2C mode while I2C_PECPositionConfig() 
+  *          is intended to used in SMBUS mode. 
+  *            
+  * @retval None
+  */
+void I2C_NACKPositionConfig(I2C_TypeDef* I2Cx, uint16_t I2C_NACKPosition)
+{
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+  assert_param(IS_I2C_NACK_POSITION(I2C_NACKPosition));
+  
+  /* Check the input parameter */
+  if (I2C_NACKPosition == I2C_NACKPosition_Next)
+  {
+    /* Next byte in shift register is the last received byte */
+    I2Cx->CR1 |= I2C_NACKPosition_Next;
+  }
+  else
+  {
+    /* Current byte in shift register is the last received byte */
+    I2Cx->CR1 &= I2C_NACKPosition_Current;
+  }
+}
+
+/**
+  * @brief  Drives the SMBusAlert pin high or low for the specified I2C.
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @param  I2C_SMBusAlert: specifies SMBAlert pin level. 
+  *          This parameter can be one of the following values:
+  *            @arg I2C_SMBusAlert_Low: SMBAlert pin driven low
+  *            @arg I2C_SMBusAlert_High: SMBAlert pin driven high
+  * @retval None
+  */
+void I2C_SMBusAlertConfig(I2C_TypeDef* I2Cx, uint16_t I2C_SMBusAlert)
+{
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+  assert_param(IS_I2C_SMBUS_ALERT(I2C_SMBusAlert));
+  if (I2C_SMBusAlert == I2C_SMBusAlert_Low)
+  {
+    /* Drive the SMBusAlert pin Low */
+    I2Cx->CR1 |= I2C_SMBusAlert_Low;
+  }
+  else
+  {
+    /* Drive the SMBusAlert pin High  */
+    I2Cx->CR1 &= I2C_SMBusAlert_High;
+  }
+}
+
+/**
+  * @brief  Enables or disables the specified I2C ARP.
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @param  NewState: new state of the I2Cx ARP. 
+  *          This parameter can be: ENABLE or DISABLE.
+  * @retval None
+  */
+void I2C_ARPCmd(I2C_TypeDef* I2Cx, FunctionalState NewState)
+{
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+  assert_param(IS_FUNCTIONAL_STATE(NewState));
+  if (NewState != DISABLE)
+  {
+    /* Enable the selected I2C ARP */
+    I2Cx->CR1 |= I2C_CR1_ENARP;
+  }
+  else
+  {
+    /* Disable the selected I2C ARP */
+    I2Cx->CR1 &= (uint16_t)~((uint16_t)I2C_CR1_ENARP);
+  }
+}
+/**
+  * @}
+  */
+
+/** @defgroup I2C_Group2 Data transfers functions
+ *  @brief   Data transfers functions 
+ *
+@verbatim   
+ ===============================================================================
+                        Data transfers functions
+ ===============================================================================  
+
+@endverbatim
+  * @{
+  */
+
+/**
+  * @brief  Sends a data byte through the I2Cx peripheral.
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @param  Data: Byte to be transmitted..
+  * @retval None
+  */
+void I2C_SendData(I2C_TypeDef* I2Cx, uint8_t Data)
+{
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+  /* Write in the DR register the data to be sent */
+  I2Cx->DR = Data;
+}
+
+/**
+  * @brief  Returns the most recent received data by the I2Cx peripheral.
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @retval The value of the received data.
+  */
+uint8_t I2C_ReceiveData(I2C_TypeDef* I2Cx)
+{
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+  /* Return the data in the DR register */
+  return (uint8_t)I2Cx->DR;
+}
+
+/**
+  * @}
+  */
+
+/** @defgroup I2C_Group3 PEC management functions
+ *  @brief   PEC management functions 
+ *
+@verbatim   
+ ===============================================================================
+                         PEC management functions
+ ===============================================================================  
+
+@endverbatim
+  * @{
+  */
+
+/**
+  * @brief  Enables or disables the specified I2C PEC transfer.
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @param  NewState: new state of the I2C PEC transmission.
+  *          This parameter can be: ENABLE or DISABLE.
+  * @retval None
+  */
+void I2C_TransmitPEC(I2C_TypeDef* I2Cx, FunctionalState NewState)
+{
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+  assert_param(IS_FUNCTIONAL_STATE(NewState));
+  if (NewState != DISABLE)
+  {
+    /* Enable the selected I2C PEC transmission */
+    I2Cx->CR1 |= I2C_CR1_PEC;
+  }
+  else
+  {
+    /* Disable the selected I2C PEC transmission */
+    I2Cx->CR1 &= (uint16_t)~((uint16_t)I2C_CR1_PEC);
+  }
+}
+
+/**
+  * @brief  Selects the specified I2C PEC position.
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @param  I2C_PECPosition: specifies the PEC position. 
+  *          This parameter can be one of the following values:
+  *            @arg I2C_PECPosition_Next: indicates that the next byte is PEC
+  *            @arg I2C_PECPosition_Current: indicates that current byte is PEC
+  *       
+  * @note    This function configures the same bit (POS) as I2C_NACKPositionConfig()
+  *          but is intended to be used in SMBUS mode while I2C_NACKPositionConfig() 
+  *          is intended to used in I2C mode.
+  *                
+  * @retval None
+  */
+void I2C_PECPositionConfig(I2C_TypeDef* I2Cx, uint16_t I2C_PECPosition)
+{
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+  assert_param(IS_I2C_PEC_POSITION(I2C_PECPosition));
+  if (I2C_PECPosition == I2C_PECPosition_Next)
+  {
+    /* Next byte in shift register is PEC */
+    I2Cx->CR1 |= I2C_PECPosition_Next;
+  }
+  else
+  {
+    /* Current byte in shift register is PEC */
+    I2Cx->CR1 &= I2C_PECPosition_Current;
+  }
+}
+
+/**
+  * @brief  Enables or disables the PEC value calculation of the transferred bytes.
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @param  NewState: new state of the I2Cx PEC value calculation.
+  *          This parameter can be: ENABLE or DISABLE.
+  * @retval None
+  */
+void I2C_CalculatePEC(I2C_TypeDef* I2Cx, FunctionalState NewState)
+{
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+  assert_param(IS_FUNCTIONAL_STATE(NewState));
+  if (NewState != DISABLE)
+  {
+    /* Enable the selected I2C PEC calculation */
+    I2Cx->CR1 |= I2C_CR1_ENPEC;
+  }
+  else
+  {
+    /* Disable the selected I2C PEC calculation */
+    I2Cx->CR1 &= (uint16_t)~((uint16_t)I2C_CR1_ENPEC);
+  }
+}
+
+/**
+  * @brief  Returns the PEC value for the specified I2C.
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @retval The PEC value.
+  */
+uint8_t I2C_GetPEC(I2C_TypeDef* I2Cx)
+{
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+  /* Return the selected I2C PEC value */
+  return ((I2Cx->SR2) >> 8);
+}
+
+/**
+  * @}
+  */
+
+/** @defgroup I2C_Group4 DMA transfers management functions
+ *  @brief   DMA transfers management functions 
+ *
+@verbatim   
+ ===============================================================================
+                         DMA transfers management functions
+ ===============================================================================  
+  This section provides functions allowing to configure the I2C DMA channels 
+  requests.
+  
+@endverbatim
+  * @{
+  */
+
+/**
+  * @brief  Enables or disables the specified I2C DMA requests.
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @param  NewState: new state of the I2C DMA transfer.
+  *          This parameter can be: ENABLE or DISABLE.
+  * @retval None
+  */
+void I2C_DMACmd(I2C_TypeDef* I2Cx, FunctionalState NewState)
+{
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+  assert_param(IS_FUNCTIONAL_STATE(NewState));
+  if (NewState != DISABLE)
+  {
+    /* Enable the selected I2C DMA requests */
+    I2Cx->CR2 |= I2C_CR2_DMAEN;
+  }
+  else
+  {
+    /* Disable the selected I2C DMA requests */
+    I2Cx->CR2 &= (uint16_t)~((uint16_t)I2C_CR2_DMAEN);
+  }
+}
+
+/**
+  * @brief  Specifies that the next DMA transfer is the last one.
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @param  NewState: new state of the I2C DMA last transfer.
+  *          This parameter can be: ENABLE or DISABLE.
+  * @retval None
+  */
+void I2C_DMALastTransferCmd(I2C_TypeDef* I2Cx, FunctionalState NewState)
+{
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+  assert_param(IS_FUNCTIONAL_STATE(NewState));
+  if (NewState != DISABLE)
+  {
+    /* Next DMA transfer is the last transfer */
+    I2Cx->CR2 |= I2C_CR2_LAST;
+  }
+  else
+  {
+    /* Next DMA transfer is not the last transfer */
+    I2Cx->CR2 &= (uint16_t)~((uint16_t)I2C_CR2_LAST);
+  }
+}
+
+/**
+  * @}
+  */
+
+/** @defgroup I2C_Group5 Interrupts events and flags management functions
+ *  @brief   Interrupts, events and flags management functions
+ *
+@verbatim   
+ ===============================================================================
+                Interrupts, events and flags management functions
+ ===============================================================================  
+  This section provides functions allowing to configure the I2C Interrupts 
+  sources and check or clear the flags or pending bits status.
+  The user should identify which mode will be used in his application to manage 
+  the communication: Polling mode, Interrupt mode or DMA mode. 
+
+ ===============================================================================
+                          I2C State Monitoring Functions                    
+ ===============================================================================   
+  This I2C driver provides three different ways for I2C state monitoring
+  depending on the application requirements and constraints:
+         
+   
+     1. Basic state monitoring (Using I2C_CheckEvent() function)
+     -----------------------------------------------------------
+        It compares the status registers (SR1 and SR2) content to a given event
+        (can be the combination of one or more flags).
+        It returns SUCCESS if the current status includes the given flags 
+        and returns ERROR if one or more flags are missing in the current status.
+
+          - When to use
+             - This function is suitable for most applications as well as for startup 
+               activity since the events are fully described in the product reference 
+               manual (RM0090).
+             - It is also suitable for users who need to define their own events.
+
+          - Limitations
+             - If an error occurs (ie. error flags are set besides to the monitored 
+               flags), the I2C_CheckEvent() function may return SUCCESS despite 
+               the communication hold or corrupted real state. 
+               In this case, it is advised to use error interrupts to monitor 
+               the error events and handle them in the interrupt IRQ handler.
+         
+     @note 
+         For error management, it is advised to use the following functions:
+           - I2C_ITConfig() to configure and enable the error interrupts (I2C_IT_ERR).
+           - I2Cx_ER_IRQHandler() which is called when the error interrupt occurs.
+             Where x is the peripheral instance (I2C1, I2C2 ...)
+           - I2C_GetFlagStatus() or I2C_GetITStatus()  to be called into the 
+             I2Cx_ER_IRQHandler() function in order to determine which error occurred.
+           - I2C_ClearFlag() or I2C_ClearITPendingBit() and/or I2C_SoftwareResetCmd() 
+             and/or I2C_GenerateStop() in order to clear the error flag and source 
+             and return to correct  communication status.
+             
+ 
+     2. Advanced state monitoring (Using the function I2C_GetLastEvent())
+     -------------------------------------------------------------------- 
+        Using the function I2C_GetLastEvent() which returns the image of both status 
+        registers in a single word (uint32_t) (Status Register 2 value is shifted left 
+        by 16 bits and concatenated to Status Register 1).
+
+          - When to use
+             - This function is suitable for the same applications above but it 
+               allows to overcome the mentioned limitation of I2C_GetFlagStatus() 
+               function.
+             - The returned value could be compared to events already defined in 
+               the library (stm32f4xx_i2c.h) or to custom values defined by user.
+               This function is suitable when multiple flags are monitored at the 
+               same time.
+             - At the opposite of I2C_CheckEvent() function, this function allows 
+               user to choose when an event is accepted (when all events flags are 
+               set and no other flags are set or just when the needed flags are set 
+               like I2C_CheckEvent() function.
+
+          - Limitations
+             - User may need to define his own events.
+             - Same remark concerning the error management is applicable for this 
+               function if user decides to check only regular communication flags 
+               (and ignores error flags).
+      
+ 
+     3. Flag-based state monitoring (Using the function I2C_GetFlagStatus())
+     -----------------------------------------------------------------------
+     
+      Using the function I2C_GetFlagStatus() which simply returns the status of 
+      one single flag (ie. I2C_FLAG_RXNE ...). 
+
+          - When to use
+             - This function could be used for specific applications or in debug 
+               phase.
+             - It is suitable when only one flag checking is needed (most I2C 
+               events are monitored through multiple flags).
+          - Limitations: 
+             - When calling this function, the Status register is accessed. 
+               Some flags are cleared when the status register is accessed. 
+               So checking the status of one Flag, may clear other ones.
+             - Function may need to be called twice or more in order to monitor 
+               one single event.
+ 
+   For detailed description of Events, please refer to section I2C_Events in 
+   stm32f4xx_i2c.h file.
+       
+@endverbatim
+  * @{
+  */
+   
+/**
+  * @brief  Reads the specified I2C register and returns its value.
+  * @param  I2C_Register: specifies the register to read.
+  *          This parameter can be one of the following values:
+  *            @arg I2C_Register_CR1:  CR1 register.
+  *            @arg I2C_Register_CR2:   CR2 register.
+  *            @arg I2C_Register_OAR1:  OAR1 register.
+  *            @arg I2C_Register_OAR2:  OAR2 register.
+  *            @arg I2C_Register_DR:    DR register.
+  *            @arg I2C_Register_SR1:   SR1 register.
+  *            @arg I2C_Register_SR2:   SR2 register.
+  *            @arg I2C_Register_CCR:   CCR register.
+  *            @arg I2C_Register_TRISE: TRISE register.
+  * @retval The value of the read register.
+  */
+uint16_t I2C_ReadRegister(I2C_TypeDef* I2Cx, uint8_t I2C_Register)
+{
+  __IO uint32_t tmp = 0;
+
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+  assert_param(IS_I2C_REGISTER(I2C_Register));
+
+  tmp = (uint32_t) I2Cx;
+  tmp += I2C_Register;
+
+  /* Return the selected register value */
+  return (*(__IO uint16_t *) tmp);
+}
+
+/**
+  * @brief  Enables or disables the specified I2C interrupts.
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @param  I2C_IT: specifies the I2C interrupts sources to be enabled or disabled. 
+  *          This parameter can be any combination of the following values:
+  *            @arg I2C_IT_BUF: Buffer interrupt mask
+  *            @arg I2C_IT_EVT: Event interrupt mask
+  *            @arg I2C_IT_ERR: Error interrupt mask
+  * @param  NewState: new state of the specified I2C interrupts.
+  *          This parameter can be: ENABLE or DISABLE.
+  * @retval None
+  */
+void I2C_ITConfig(I2C_TypeDef* I2Cx, uint16_t I2C_IT, FunctionalState NewState)
+{
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+  assert_param(IS_FUNCTIONAL_STATE(NewState));
+  assert_param(IS_I2C_CONFIG_IT(I2C_IT));
+  
+  if (NewState != DISABLE)
+  {
+    /* Enable the selected I2C interrupts */
+    I2Cx->CR2 |= I2C_IT;
+  }
+  else
+  {
+    /* Disable the selected I2C interrupts */
+    I2Cx->CR2 &= (uint16_t)~I2C_IT;
+  }
+}
+
+/*
+ ===============================================================================
+                          1. Basic state monitoring                    
+ ===============================================================================  
+ */
+
+/**
+  * @brief  Checks whether the last I2Cx Event is equal to the one passed
+  *         as parameter.
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @param  I2C_EVENT: specifies the event to be checked. 
+  *          This parameter can be one of the following values:
+  *            @arg I2C_EVENT_SLAVE_TRANSMITTER_ADDRESS_MATCHED: EV1
+  *            @arg I2C_EVENT_SLAVE_RECEIVER_ADDRESS_MATCHED: EV1
+  *            @arg I2C_EVENT_SLAVE_TRANSMITTER_SECONDADDRESS_MATCHED: EV1
+  *            @arg I2C_EVENT_SLAVE_RECEIVER_SECONDADDRESS_MATCHED: EV1
+  *            @arg I2C_EVENT_SLAVE_GENERALCALLADDRESS_MATCHED: EV1
+  *            @arg I2C_EVENT_SLAVE_BYTE_RECEIVED: EV2
+  *            @arg (I2C_EVENT_SLAVE_BYTE_RECEIVED | I2C_FLAG_DUALF): EV2
+  *            @arg (I2C_EVENT_SLAVE_BYTE_RECEIVED | I2C_FLAG_GENCALL): EV2
+  *            @arg I2C_EVENT_SLAVE_BYTE_TRANSMITTED: EV3
+  *            @arg (I2C_EVENT_SLAVE_BYTE_TRANSMITTED | I2C_FLAG_DUALF): EV3
+  *            @arg (I2C_EVENT_SLAVE_BYTE_TRANSMITTED | I2C_FLAG_GENCALL): EV3
+  *            @arg I2C_EVENT_SLAVE_ACK_FAILURE: EV3_2
+  *            @arg I2C_EVENT_SLAVE_STOP_DETECTED: EV4
+  *            @arg I2C_EVENT_MASTER_MODE_SELECT: EV5
+  *            @arg I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED: EV6     
+  *            @arg I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED: EV6
+  *            @arg I2C_EVENT_MASTER_BYTE_RECEIVED: EV7
+  *            @arg I2C_EVENT_MASTER_BYTE_TRANSMITTING: EV8
+  *            @arg I2C_EVENT_MASTER_BYTE_TRANSMITTED: EV8_2
+  *            @arg I2C_EVENT_MASTER_MODE_ADDRESS10: EV9
+  *     
+  * @note   For detailed description of Events, please refer to section I2C_Events
+  *         in stm32f4xx_i2c.h file.
+  *    
+  * @retval An ErrorStatus enumeration value:
+  *           - SUCCESS: Last event is equal to the I2C_EVENT
+  *           - ERROR: Last event is different from the I2C_EVENT
+  */
+ErrorStatus I2C_CheckEvent(I2C_TypeDef* I2Cx, uint32_t I2C_EVENT)
+{
+  uint32_t lastevent = 0;
+  uint32_t flag1 = 0, flag2 = 0;
+  ErrorStatus status = ERROR;
+
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+  assert_param(IS_I2C_EVENT(I2C_EVENT));
+
+  /* Read the I2Cx status register */
+  flag1 = I2Cx->SR1;
+  flag2 = I2Cx->SR2;
+  flag2 = flag2 << 16;
+
+  /* Get the last event value from I2C status register */
+  lastevent = (flag1 | flag2) & FLAG_MASK;
+
+  /* Check whether the last event contains the I2C_EVENT */
+  if ((lastevent & I2C_EVENT) == I2C_EVENT)
+  {
+    /* SUCCESS: last event is equal to I2C_EVENT */
+    status = SUCCESS;
+  }
+  else
+  {
+    /* ERROR: last event is different from I2C_EVENT */
+    status = ERROR;
+  }
+  /* Return status */
+  return status;
+}
+
+/*
+ ===============================================================================
+                          2. Advanced state monitoring                   
+ ===============================================================================  
+ */
+
+/**
+  * @brief  Returns the last I2Cx Event.
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  *     
+  * @note   For detailed description of Events, please refer to section I2C_Events
+  *         in stm32f4xx_i2c.h file.
+  *    
+  * @retval The last event
+  */
+uint32_t I2C_GetLastEvent(I2C_TypeDef* I2Cx)
+{
+  uint32_t lastevent = 0;
+  uint32_t flag1 = 0, flag2 = 0;
+
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+
+  /* Read the I2Cx status register */
+  flag1 = I2Cx->SR1;
+  flag2 = I2Cx->SR2;
+  flag2 = flag2 << 16;
+
+  /* Get the last event value from I2C status register */
+  lastevent = (flag1 | flag2) & FLAG_MASK;
+
+  /* Return status */
+  return lastevent;
+}
+
+/*
+ ===============================================================================
+                          3. Flag-based state monitoring                   
+ ===============================================================================  
+ */
+
+/**
+  * @brief  Checks whether the specified I2C flag is set or not.
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @param  I2C_FLAG: specifies the flag to check. 
+  *          This parameter can be one of the following values:
+  *            @arg I2C_FLAG_DUALF: Dual flag (Slave mode)
+  *            @arg I2C_FLAG_SMBHOST: SMBus host header (Slave mode)
+  *            @arg I2C_FLAG_SMBDEFAULT: SMBus default header (Slave mode)
+  *            @arg I2C_FLAG_GENCALL: General call header flag (Slave mode)
+  *            @arg I2C_FLAG_TRA: Transmitter/Receiver flag
+  *            @arg I2C_FLAG_BUSY: Bus busy flag
+  *            @arg I2C_FLAG_MSL: Master/Slave flag
+  *            @arg I2C_FLAG_SMBALERT: SMBus Alert flag
+  *            @arg I2C_FLAG_TIMEOUT: Timeout or Tlow error flag
+  *            @arg I2C_FLAG_PECERR: PEC error in reception flag
+  *            @arg I2C_FLAG_OVR: Overrun/Underrun flag (Slave mode)
+  *            @arg I2C_FLAG_AF: Acknowledge failure flag
+  *            @arg I2C_FLAG_ARLO: Arbitration lost flag (Master mode)
+  *            @arg I2C_FLAG_BERR: Bus error flag
+  *            @arg I2C_FLAG_TXE: Data register empty flag (Transmitter)
+  *            @arg I2C_FLAG_RXNE: Data register not empty (Receiver) flag
+  *            @arg I2C_FLAG_STOPF: Stop detection flag (Slave mode)
+  *            @arg I2C_FLAG_ADD10: 10-bit header sent flag (Master mode)
+  *            @arg I2C_FLAG_BTF: Byte transfer finished flag
+  *            @arg I2C_FLAG_ADDR: Address sent flag (Master mode) "ADSL"
+  *                                Address matched flag (Slave mode)"ENDAD"
+  *            @arg I2C_FLAG_SB: Start bit flag (Master mode)
+  * @retval The new state of I2C_FLAG (SET or RESET).
+  */
+FlagStatus I2C_GetFlagStatus(I2C_TypeDef* I2Cx, uint32_t I2C_FLAG)
+{
+  FlagStatus bitstatus = RESET;
+  __IO uint32_t i2creg = 0, i2cxbase = 0;
+
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+  assert_param(IS_I2C_GET_FLAG(I2C_FLAG));
+
+  /* Get the I2Cx peripheral base address */
+  i2cxbase = (uint32_t)I2Cx;
+  
+  /* Read flag register index */
+  i2creg = I2C_FLAG >> 28;
+  
+  /* Get bit[23:0] of the flag */
+  I2C_FLAG &= FLAG_MASK;
+  
+  if(i2creg != 0)
+  {
+    /* Get the I2Cx SR1 register address */
+    i2cxbase += 0x14;
+  }
+  else
+  {
+    /* Flag in I2Cx SR2 Register */
+    I2C_FLAG = (uint32_t)(I2C_FLAG >> 16);
+    /* Get the I2Cx SR2 register address */
+    i2cxbase += 0x18;
+  }
+  
+  if(((*(__IO uint32_t *)i2cxbase) & I2C_FLAG) != (uint32_t)RESET)
+  {
+    /* I2C_FLAG is set */
+    bitstatus = SET;
+  }
+  else
+  {
+    /* I2C_FLAG is reset */
+    bitstatus = RESET;
+  }
+  
+  /* Return the I2C_FLAG status */
+  return  bitstatus;
+}
+
+/**
+  * @brief  Clears the I2Cx's pending flags.
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @param  I2C_FLAG: specifies the flag to clear. 
+  *          This parameter can be any combination of the following values:
+  *            @arg I2C_FLAG_SMBALERT: SMBus Alert flag
+  *            @arg I2C_FLAG_TIMEOUT: Timeout or Tlow error flag
+  *            @arg I2C_FLAG_PECERR: PEC error in reception flag
+  *            @arg I2C_FLAG_OVR: Overrun/Underrun flag (Slave mode)
+  *            @arg I2C_FLAG_AF: Acknowledge failure flag
+  *            @arg I2C_FLAG_ARLO: Arbitration lost flag (Master mode)
+  *            @arg I2C_FLAG_BERR: Bus error flag
+  *   
+  * @note   STOPF (STOP detection) is cleared by software sequence: a read operation 
+  *          to I2C_SR1 register (I2C_GetFlagStatus()) followed by a write operation 
+  *          to I2C_CR1 register (I2C_Cmd() to re-enable the I2C peripheral).
+  * @note   ADD10 (10-bit header sent) is cleared by software sequence: a read 
+  *          operation to I2C_SR1 (I2C_GetFlagStatus()) followed by writing the 
+  *          second byte of the address in DR register.
+  * @note   BTF (Byte Transfer Finished) is cleared by software sequence: a read 
+  *          operation to I2C_SR1 register (I2C_GetFlagStatus()) followed by a 
+  *          read/write to I2C_DR register (I2C_SendData()).
+  * @note   ADDR (Address sent) is cleared by software sequence: a read operation to 
+  *          I2C_SR1 register (I2C_GetFlagStatus()) followed by a read operation to 
+  *          I2C_SR2 register ((void)(I2Cx->SR2)).
+  * @note   SB (Start Bit) is cleared software sequence: a read operation to I2C_SR1
+  *          register (I2C_GetFlagStatus()) followed by a write operation to I2C_DR
+  *          register (I2C_SendData()).
+  *  
+  * @retval None
+  */
+void I2C_ClearFlag(I2C_TypeDef* I2Cx, uint32_t I2C_FLAG)
+{
+  uint32_t flagpos = 0;
+  /* Check the parameters */
+  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
+  assert_param(IS_I2C_CLEAR_FLAG(I2C_FLAG));
+  /* Get the I2C flag position */
+  flagpos = I2C_FLAG & FLAG_MASK;
+  /* Clear the selected I2C flag */
+  I2Cx->SR1 = (uint16_t)~flagpos;
+}
+
+/**
+  * @brief  Checks whether the specified I2C interrupt has occurred or not.
+  * @param  I2Cx: where x can be 1, 2 or 3 to select the I2C peripheral.
+  * @param  I2C_IT: specifies the interrupt source to check. 
+  *          This parameter can be one of the following values:
+  *            @arg I2C_IT_SMBALERT: SMBus Alert flag
+  *            @arg I2C_IT_TIMEOUT: Timeout or Tlow error flag
+  *            @arg I2C_IT_PECERR: PEC error in reception flag
+  *            @arg I2C_IT_OVR: Overrun/Underrun flag (Slave mode)
+  *            @arg I2C_IT_AF: Acknowledge failure flag
+  *            @arg I2C_IT_ARLO: Arbitration lost flag (Master mode)
+  *            @arg I2C_IT_BERR: Bus error flag
+  *            @arg I2C_IT_TXE: Data register empty flag (Transmitter)
+  *            @arg I2C_IT_RXNE: Data register not empty (Receiver) flag
+  *            @arg I2C_IT_STOPF: Stop detection flag (Slave mode)
+  *            @arg I2C_IT_ADD10: 10-bit header sent flag (Master mode)
+  *            @arg I2C_IT_BTF: Byte transfer finished flag
+  *            @arg I2C_IT_ADDR: Address sent flag (Master mode) "ADSL"
+  *                              Address matched flag (Slave mode)"ENDAD"
+  *            @arg I2C_IT_SB: Start bit flag (Master mode)
+  * @retval The new state of I2C_IT (SET or RESET).
+  */
+ITStatus I2C_GetITStatus(I2C_TypeDef* I2Cx, uint32_t I2C_IT)
+{
+  ITStatus bitstatus = RESET;
+  uint32_t enablestatus = 0;