Interrupts, events and flags management functions. More...

Functions
uint16_t	I2C_ReadRegister (I2C_TypeDef *I2Cx, uint8_t I2C_Register)
	Reads the specified I2C register and returns its value. More...

void	I2C_ITConfig (I2C_TypeDef *I2Cx, uint16_t I2C_IT, FunctionalState NewState)
	Enables or disables the specified I2C interrupts. More...

ErrorStatus	I2C_CheckEvent (I2C_TypeDef *I2Cx, uint32_t I2C_EVENT)
	Checks whether the last I2Cx Event is equal to the one passed as parameter. More...

uint32_t	I2C_GetLastEvent (I2C_TypeDef *I2Cx)
	Returns the last I2Cx Event. More...

FlagStatus	I2C_GetFlagStatus (I2C_TypeDef *I2Cx, uint32_t I2C_FLAG)
	Checks whether the specified I2C flag is set or not. More...

void	I2C_ClearFlag (I2C_TypeDef *I2Cx, uint32_t I2C_FLAG)
	Clears the I2Cx's pending flags. More...

ITStatus	I2C_GetITStatus (I2C_TypeDef *I2Cx, uint32_t I2C_IT)
	Checks whether the specified I2C interrupt has occurred or not. More...

void	I2C_ClearITPendingBit (I2C_TypeDef *I2Cx, uint32_t I2C_IT)
	Clears the I2Cx's interrupt pending bits. More...

Detailed Description

Interrupts, events and flags management functions.

 ===============================================================================
                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.

Function Documentation

ErrorStatus I2C_CheckEvent	(	I2C_TypeDef *	I2Cx,
		uint32_t	I2C_EVENT
	)

Checks whether the last I2Cx Event is equal to the one passed as parameter.

Parameters

I2Cx,: where x can be 1, 2 or 3 to select the I2C peripheral.

I2C_EVENT,:

specifies the event to be checked. This parameter can be one of the following values:

I2C_EVENT_SLAVE_TRANSMITTER_ADDRESS_MATCHED: EV1
I2C_EVENT_SLAVE_RECEIVER_ADDRESS_MATCHED: EV1
I2C_EVENT_SLAVE_TRANSMITTER_SECONDADDRESS_MATCHED: EV1
I2C_EVENT_SLAVE_RECEIVER_SECONDADDRESS_MATCHED: EV1
I2C_EVENT_SLAVE_GENERALCALLADDRESS_MATCHED: EV1
I2C_EVENT_SLAVE_BYTE_RECEIVED: EV2
(I2C_EVENT_SLAVE_BYTE_RECEIVED | I2C_FLAG_DUALF): EV2
(I2C_EVENT_SLAVE_BYTE_RECEIVED | I2C_FLAG_GENCALL): EV2
I2C_EVENT_SLAVE_BYTE_TRANSMITTED: EV3
(I2C_EVENT_SLAVE_BYTE_TRANSMITTED | I2C_FLAG_DUALF): EV3
(I2C_EVENT_SLAVE_BYTE_TRANSMITTED | I2C_FLAG_GENCALL): EV3
I2C_EVENT_SLAVE_ACK_FAILURE: EV3_2
I2C_EVENT_SLAVE_STOP_DETECTED: EV4
I2C_EVENT_MASTER_MODE_SELECT: EV5
I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED: EV6
I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED: EV6
I2C_EVENT_MASTER_BYTE_RECEIVED: EV7
I2C_EVENT_MASTER_BYTE_TRANSMITTING: EV8
I2C_EVENT_MASTER_BYTE_TRANSMITTED: EV8_2
I2C_EVENT_MASTER_MODE_ADDRESS10: EV9

Note: For detailed description of Events, please refer to section I2C_Events in stm32f4xx_i2c.h file.

Return values

An	ErrorStatus enumeration value: SUCCESS: Last event is equal to the I2C_EVENT ERROR: Last event is different from the I2C_EVENT

void I2C_ClearFlag	(	I2C_TypeDef *	I2Cx,
		uint32_t	I2C_FLAG
	)

Clears the I2Cx's pending flags.

Parameters

I2Cx,:	where x can be 1, 2 or 3 to select the I2C peripheral.
I2C_FLAG,:	specifies the flag to clear. This parameter can be any combination of the following values: I2C_FLAG_SMBALERT: SMBus Alert flag I2C_FLAG_TIMEOUT: Timeout or Tlow error flag I2C_FLAG_PECERR: PEC error in reception flag I2C_FLAG_OVR: Overrun/Underrun flag (Slave mode) I2C_FLAG_AF: Acknowledge failure flag I2C_FLAG_ARLO: Arbitration lost flag (Master mode) 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).; 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.; 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()).; 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)).; 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()).

Return values

None

void I2C_ClearITPendingBit	(	I2C_TypeDef *	I2Cx,
		uint32_t	I2C_IT
	)

Clears the I2Cx's interrupt pending bits.

Parameters

I2Cx,: where x can be 1, 2 or 3 to select the I2C peripheral.

I2C_IT,:

specifies the interrupt pending bit to clear. This parameter can be any combination of the following values:

I2C_IT_SMBALERT: SMBus Alert interrupt
I2C_IT_TIMEOUT: Timeout or Tlow error interrupt
I2C_IT_PECERR: PEC error in reception interrupt
I2C_IT_OVR: Overrun/Underrun interrupt (Slave mode)
I2C_IT_AF: Acknowledge failure interrupt
I2C_IT_ARLO: Arbitration lost interrupt (Master mode)
I2C_IT_BERR: Bus error interrupt

Note: STOPF (STOP detection) is cleared by software sequence: a read operation to I2C_SR1 register (I2C_GetITStatus()) followed by a write operation to I2C_CR1 register (I2C_Cmd() to re-enable the I2C peripheral).; ADD10 (10-bit header sent) is cleared by software sequence: a read operation to I2C_SR1 (I2C_GetITStatus()) followed by writing the second byte of the address in I2C_DR register.; BTF (Byte Transfer Finished) is cleared by software sequence: a read operation to I2C_SR1 register (I2C_GetITStatus()) followed by a read/write to I2C_DR register (I2C_SendData()).; ADDR (Address sent) is cleared by software sequence: a read operation to I2C_SR1 register (I2C_GetITStatus()) followed by a read operation to I2C_SR2 register ((void)(I2Cx->SR2)).; SB (Start Bit) is cleared by software sequence: a read operation to I2C_SR1 register (I2C_GetITStatus()) followed by a write operation to I2C_DR register (I2C_SendData()).

Return values

None

FlagStatus I2C_GetFlagStatus	(	I2C_TypeDef *	I2Cx,
		uint32_t	I2C_FLAG
	)

Checks whether the specified I2C flag is set or not.

Parameters

I2Cx,: where x can be 1, 2 or 3 to select the I2C peripheral.

I2C_FLAG,:

specifies the flag to check. This parameter can be one of the following values:

I2C_FLAG_DUALF: Dual flag (Slave mode)
I2C_FLAG_SMBHOST: SMBus host header (Slave mode)
I2C_FLAG_SMBDEFAULT: SMBus default header (Slave mode)
I2C_FLAG_GENCALL: General call header flag (Slave mode)
I2C_FLAG_TRA: Transmitter/Receiver flag
I2C_FLAG_BUSY: Bus busy flag
I2C_FLAG_MSL: Master/Slave flag
I2C_FLAG_SMBALERT: SMBus Alert flag
I2C_FLAG_TIMEOUT: Timeout or Tlow error flag
I2C_FLAG_PECERR: PEC error in reception flag
I2C_FLAG_OVR: Overrun/Underrun flag (Slave mode)
I2C_FLAG_AF: Acknowledge failure flag
I2C_FLAG_ARLO: Arbitration lost flag (Master mode)
I2C_FLAG_BERR: Bus error flag
I2C_FLAG_TXE: Data register empty flag (Transmitter)
I2C_FLAG_RXNE: Data register not empty (Receiver) flag
I2C_FLAG_STOPF: Stop detection flag (Slave mode)
I2C_FLAG_ADD10: 10-bit header sent flag (Master mode)
I2C_FLAG_BTF: Byte transfer finished flag
I2C_FLAG_ADDR: Address sent flag (Master mode) "ADSL" Address matched flag (Slave mode)"ENDAD"
I2C_FLAG_SB: Start bit flag (Master mode)

Return values

The	new state of I2C_FLAG (SET or RESET).

ITStatus I2C_GetITStatus	(	I2C_TypeDef *	I2Cx,
		uint32_t	I2C_IT
	)

Checks whether the specified I2C interrupt has occurred or not.

Parameters

I2Cx,: where x can be 1, 2 or 3 to select the I2C peripheral.

I2C_IT,:

specifies the interrupt source to check. This parameter can be one of the following values:

I2C_IT_SMBALERT: SMBus Alert flag
I2C_IT_TIMEOUT: Timeout or Tlow error flag
I2C_IT_PECERR: PEC error in reception flag
I2C_IT_OVR: Overrun/Underrun flag (Slave mode)
I2C_IT_AF: Acknowledge failure flag
I2C_IT_ARLO: Arbitration lost flag (Master mode)
I2C_IT_BERR: Bus error flag
I2C_IT_TXE: Data register empty flag (Transmitter)
I2C_IT_RXNE: Data register not empty (Receiver) flag
I2C_IT_STOPF: Stop detection flag (Slave mode)
I2C_IT_ADD10: 10-bit header sent flag (Master mode)
I2C_IT_BTF: Byte transfer finished flag
I2C_IT_ADDR: Address sent flag (Master mode) "ADSL" Address matched flag (Slave mode)"ENDAD"
I2C_IT_SB: Start bit flag (Master mode)

Return values

The	new state of I2C_IT (SET or RESET).

uint32_t I2C_GetLastEvent ( I2C_TypeDef * I2Cx )

Returns the last I2Cx Event.

Parameters

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.

Return values

The	last event

void I2C_ITConfig	(	I2C_TypeDef *	I2Cx,
		uint16_t	I2C_IT,
		FunctionalState	NewState
	)

Enables or disables the specified I2C interrupts.

Parameters

I2Cx,:	where x can be 1, 2 or 3 to select the I2C peripheral.
I2C_IT,:	specifies the I2C interrupts sources to be enabled or disabled. This parameter can be any combination of the following values: I2C_IT_BUF: Buffer interrupt mask I2C_IT_EVT: Event interrupt mask I2C_IT_ERR: Error interrupt mask
NewState,:	new state of the specified I2C interrupts. This parameter can be: ENABLE or DISABLE.

Return values

None

uint16_t I2C_ReadRegister	(	I2C_TypeDef *	I2Cx,
		uint8_t	I2C_Register
	)

Reads the specified I2C register and returns its value.

Parameters

I2C_Register,:

specifies the register to read. This parameter can be one of the following values:

I2C_Register_CR1: CR1 register.
I2C_Register_CR2: CR2 register.
I2C_Register_OAR1: OAR1 register.
I2C_Register_OAR2: OAR2 register.
I2C_Register_DR: DR register.
I2C_Register_SR1: SR1 register.
I2C_Register_SR2: SR2 register.
I2C_Register_CCR: CCR register.
I2C_Register_TRISE: TRISE register.

Return values

The	value of the read register.