CHIP: LPC11xx I2C driver

Event handler function type.

Definition at line 303 of file i2c_11xx.h.

I2C interface IDs.

Note:

All Chip functions will take this as the first parameter, I2C_NUM_INTERFACE must never be used for calling any Chip functions, it is only used to find the number of interfaces available in the Chip.

I2C master events.

Enumerator:

I2C_EVENT_WAIT	I2C Wait event.
I2C_EVENT_DONE	Done event that wakes up Wait event.
I2C_EVENT_LOCK	Re-entrency lock event for I2C transfer.
I2C_EVENT_UNLOCK	Re-entrency unlock event for I2C transfer.
I2C_EVENT_SLAVE_RX	Slave receive event.
I2C_EVENT_SLAVE_TX	Slave transmit event.

Definition at line 291 of file i2c_11xx.h.

I2C interface IDs.

Note:

All Chip functions will take this as the first parameter, I2C_NUM_INTERFACE must never be used for calling any Chip functions, it is only used to find the number of interfaces available in the Chip.

Enumerator:

I2C0	ID I2C0.
I2C_NUM_INTERFACE	Number of I2C interfaces in the chip.

Definition at line 283 of file i2c_11xx.h.

I2C Slave Identifiers.

Enumerator:

I2C_SLAVE_GENERAL	Slave ID for general calls.
I2C_SLAVE_0	Slave ID fo Slave Address 0.
I2C_SLAVE_1	Slave ID fo Slave Address 1.
I2C_SLAVE_2	Slave ID fo Slave Address 2.
I2C_SLAVE_3	Slave ID fo Slave Address 3.
I2C_SLAVE_NUM_INTERFACE	Number of slave interfaces.

Definition at line 241 of file i2c_11xx.h.

I2C transfer status.

Enumerator:

I2C_STATUS_DONE	Transfer done successfully.
I2C_STATUS_NAK	NAK received during transfer.
I2C_STATUS_ARBLOST	Aribitration lost during transfer.
I2C_STATUS_BUSERR	Bus error in I2C transfer.
I2C_STATUS_BUSY	I2C is busy doing transfer.

Definition at line 253 of file i2c_11xx.h.

De-initializes the I2C peripheral registers to their default reset values.

Parameters:

id	: I2C peripheral ID (I2C0, I2C1 ... etc)

Returns:

Nothing

Disable I2C peripheral's operation.

Parameters:

id	: I2C peripheral ID (I2C0, I2C1 ... etc)

Returns:

Nothing

Default event handler for interrupt base operation.

Parameters:

id	: I2C peripheral ID (I2C0, I2C1 ... etc)
event	: Event ID of the event that called the function

Returns:

Nothing

Default event handler for polling operation.

Parameters:

id	: I2C peripheral ID (I2C0, I2C1 ... etc)
event	: Event ID of the event that called the function

Returns:

Nothing

Get current clock rate for LPC_I2C peripheral.

Parameters:

id	: I2C peripheral ID (I2C0, I2C1 ... etc)

Returns:

The current I2C peripheral clock rate

Get pointer to current function handling the events.

Parameters:

id	: I2C peripheral ID (I2C0, I2C1 ... etc)

Returns:

Pointer to function handing events of I2C

Initializes the LPC_I2C peripheral with specified parameter.

Parameters:

id	: I2C peripheral ID (I2C0, I2C1 ... etc)

Returns:

Nothing

Checks if master xfer in progress.

Parameters:

id	: I2C peripheral ID (I2C0, I2C1 ... etc)

Returns:

1 if master xfer in progress 0 otherwise

Note:

This API is generally used in interrupt handler of the application to decide whether to call master state handler or to call slave state handler

I2C peripheral state change checking.

Parameters:

id	: I2C peripheral ID (I2C0, I2C1 ... etc)

Returns:

1 if I2C peripheral id has changed its state, 0 if there is no state change

Note:

This function must be used by the application when the polling has to be done based on state change.

Transfer a command to slave and receive data from slave after a repeated start.

Parameters:

id	: I2C peripheral ID (I2C0, I2C1 ... etc)
slaveAddr	: Slave address of the I2C device
cmd	: Command (Address/Register) to be written
buff	: Pointer to memory that will hold the data received
len	: Number of bytes to receive

Returns:

Number of bytes successfully received

Set function that must handle I2C events.

Parameters:

id	: I2C peripheral ID (I2C0, I2C1 ... etc)
slaveAddr	: Slave address from which data be read
buff	: Pointer to memory where data read be stored
len	: Number of bytes to read from slave

Returns:

Number of bytes read successfully

Transmit data to I2C slave using I2C Master mode.

Parameters:

id	: I2C peripheral ID (I2C0, I2C1 .. etc)
slaveAddr	: Slave address to which the data be written
buff	: Pointer to buffer having the array of data
len	: Number of bytes to be transfered from buff

Returns:

Number of bytes successfully transfered

I2C Master transfer state change handler.

Parameters:

id	: I2C peripheral ID (I2C0, I2C1 ... etc)

Returns:

Nothing

Note:

Usually called from the appropriate Interrupt handler

Transmit and Receive data in master mode.

Parameters:

id	: I2C peripheral selected (I2C0, I2C1 etc)
xfer	: Pointer to a I2C_XFER_T structure see notes below

Returns:

Any of I2C_STATUS_T values, xfer->txSz will have number of bytes not sent due to error, xfer->rxSz will have the number of bytes yet to be received.

Note:

The parameter xfer should have its member slaveAddr initialized to the 7-Bit slave address to which the master will do the xfer, Bit0 to bit6 should have the address and Bit8 is ignored. During the transfer no code (like event handler) must change the content of the memory pointed to by xfer. The member of xfer, txBuff and txSz be initialized to the memory from which the I2C must pick the data to be transfered to slave and the number of bytes to send respectively, similarly rxBuff and rxSz must have pointer to memroy where data received from slave be stored and the number of data to get from slave respectilvely.

Set up clock rate for LPC_I2C peripheral.

Parameters:

id	: I2C peripheral ID (I2C0, I2C1 ... etc)
clockrate	: Target clock rate value to initialized I2C peripheral (Hz)

Returns:

Nothing

Note:

Parameter clockrate for I2C0 should be from 1000 up to 1000000 (1 KHz to 1 MHz), as I2C0 support Fast Mode Plus. If the clockrate is more than 400 KHz (Fast Plus Mode) Board_I2C_EnableFastPlus() must be called prior to calling this function.

Set function that must handle I2C events.

Parameters:

id	: I2C peripheral ID (I2C0, I2C1 ... etc)
event	: Pointer to function that will handle the event (Should not be NULL)

Returns:

1 when successful, 0 when a transfer is on going with its own event handler

Setup a slave I2C device.

Parameters:

id	: I2C peripheral ID (I2C0, I2C1 ... etc)
sid	: I2C Slave peripheral ID (I2C_SLAVE_0, I2C_SLAVE_1 etc)
xfer	: Pointer to transfer structure (see note below for more info)
event	: Event handler for slave transfers
addrMask	: Address mask to use along with slave address (see notes below for more info)

Returns:

Nothing

Note:

Parameter xfer should point to a valid I2C_XFER_T structure object and must have slaveAddr initialized with 7bit Slave address (From Bit1 to Bit7), Bit0 when set enables general call handling, slaveAddr along with addrMask will be used to match the slave address. rxBuff and txBuff must point to valid buffers where slave can receive or send the data from, size of which will be provided by rxSz and txSz respectively. Function pointed to by event will be called for the following events I2C_EVENT_SLAVE_RX (One byte of data received successfully from the master and stored inside memory pointed by xfer->rxBuff, incremented the pointer and decremented the xfer->rxSz), I2C_EVENT_SLAVE_TX (One byte of data from xfer->txBuff was sent to master successfully, incremented the pointer and decremented xfer->txSz), I2C_EVENT_DONE (Master is done doing its transfers with the slave).

Bit-0 of the parameter addrMask is reserved and should always be 0. Any bit (BIT1 to BIT7) set in addrMask will make the corresponding bit in *xfer->slaveAddr* as don't care. Thit is, if *xfer->slaveAddr* is (0x10 << 1) and addrMask is (0x03 << 1) then 0x10, 0x11, 0x12, 0x13 will all be considered as valid slave addresses for the registered slave. Upon receving any event *xfer->slaveAddr* (BIT1 to BIT7) will hold the actual address which was received from master.

General Call Handling
Slave can receive data from master using general call address (0x00). General call handling must be setup as given below

• Call Chip_I2C_SlaveSetup() with argument sid as I2C_SLAVE_GENERAL
  • xfer->slaveAddr ignored, argument addrMask ignored
  • function provided by event will registered to be called when slave received data using addr 0x00
  • xfer->rxBuff and xfer->rxSz should be valid in argument xfer
• To handle General Call only (No other slaves are configured)
  • Call Chip_I2C_SlaveSetup() with sid as I2C_SLAVE_X (X=0,1,2,3)
  • setup xfer with slaveAddr member set to 0, event is ignored hence can be NULL
  • provide addrMask (typically 0, if not you better be knowing what you are doing)
• To handler General Call when other slave is active
  • Call Chip_I2C_SlaveSetup() with sid as I2C_SLAVE_X (X=0,1,2,3)
  • setup xfer with slaveAddr member set to 7-Bit Slave address [from Bit1 to 7]
  • Set Bit0 of xfer->slaveAddr as 1
  • Provide appropriate addrMask
  • Argument event must point to function, that handles events from actual slaveAddress and not the GC

Warning:

If the slave has only one byte in its txBuff, once that byte is transfered to master the event handler will be called for event I2C_EVENT_DONE. If the master attempts to read more bytes in the same transfer then the slave hardware will send 0xFF to master till the end of transfer, event handler will not be called to notify this. For more info see section below

Last data handling in slave
If the user wants to implement a slave which will read a byte from a specific location over and over again whenever master reads the slave. If the user initializes the xfer->txBuff as the location to read the byte from and xfer->txSz as 1, then say, if master reads one byte; slave will send the byte read from xfer->txBuff and will call the event handler with I2C_EVENT_DONE. If the master attempts to read another byte instead of sending the byte read from xfer->txBuff the slave hardware will send 0xFF and no event will occur. To handle this issue, slave should set xfer->txSz to 2, in which case when master reads the byte event handler will be called with I2C_EVENT_SLAVE_TX, in which the slave implementation can reset the buffer and size back to original location (i.e, xfer->txBuff--, xfer->txSz++), if the master reads another byte in the same transfer, byte read from xfer->txBuff will be sent and I2C_EVENT_SLAVE_TX will be called again, and the process repeats.

I2C Slave event handler.

Parameters:

id	: I2C peripheral ID (I2C0, I2C1 ... etc)

Returns:

Nothing