Interrupts, events and flags management functions.
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Interrupts, events and flags management functions.
Data transfers 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:
(#) 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.
-@@- 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.
(#) 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).
(#) 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.
===============================================================================
##### Data transfers management functions #####
===============================================================================
[..] This subsection provides a set of functions allowing to manage
the I2C data transfers.
[..] The read access of the I2C_RXDR register can be done using
the I2C_ReceiveData() function and returns the received value.
Whereas a write access to the I2C_TXDR can be done using I2C_SendData()
function and stores the written data into TXDR.
Checks whether the last I2Cx Event is equal to the one passed as parameter.
I2C State Monitoring Functions.
- 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
|
Definition at line 1152 of file stm32f4xx_i2c.c.
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
-
Definition at line 1332 of file stm32f4xx_i2c.c.
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
-
Definition at line 1426 of file stm32f4xx_i2c.c.
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). |
Definition at line 1255 of file stm32f4xx_i2c.c.
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). |
Definition at line 1366 of file stm32f4xx_i2c.c.
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
-
Definition at line 1200 of file stm32f4xx_i2c.c.
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
-
Definition at line 1093 of file stm32f4xx_i2c.c.
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. |
Definition at line 1066 of file stm32f4xx_i2c.c.
Returns the most recent received data by the I2Cx peripheral.
- Parameters
-
I2Cx | where x can be 1 or 2 to select the I2C peripheral. |
- Return values
-
The | value of the received data. |
Definition at line 1258 of file stm32f30x_i2c.c.
Sends a data byte through the I2Cx peripheral.
- Parameters
-
I2Cx | where x can be 1 or 2 to select the I2C peripheral. |
Data | Byte to be transmitted.. |
- Return values
-
Definition at line 1244 of file stm32f30x_i2c.c.