See Quickstart guide for SAM TWIS driver.

Driver for the TWIS (Two-Wire Slave Interface). This driver provides access to the main features of the TWIS controller. The TWIS interconnects components on a unique two-wire bus. The TWIS is programmable as a slave with sequential or single-byte access. High speed mode capability is supported.

Data Structures
struct	twis_callback

struct	twis_config
	Input parameters when initializing the TWIS module mode. More...

struct	twis_dev_inst
	TWI slave driver software instance structure. More...

Macros
#define	TWIS_WAIT_TIMEOUT 1000

Typedefs
typedef struct twis_callback	twis_callback_t

typedef enum twis_interrupt_source	twis_interrupt_source_t
	TWIS interrupt source type. More...

Enumerations
enum	twis_interrupt_source { TWIS_INTERRUPT_RX_BUFFER_READY = TWIS_IER_RXRDY, TWIS_INTERRUPT_TX_BUFFER_READY = TWIS_IER_TXRDY, TWIS_INTERRUPT_TRANS_COMP = TWIS_IER_TCOMP, TWIS_INTERRUPT_UNDER_RUN = TWIS_IER_URUN, TWIS_INTERRUPT_OVER_RUN = TWIS_IER_ORUN, TWIS_INTERRUPT_NAK_RECEIVED = TWIS_IER_NAK, TWIS_INTERRUPT_SMBUS_TIMEOUT = TWIS_IER_SMBTOUT, TWIS_INTERRUPT_SMBUS_PEC_ERROR = TWIS_IER_SMBPECERR, TWIS_INTERRUPT_BUS_ERROR = TWIS_IER_BUSERR, TWIS_INTERRUPT_SLAVEADR_MATCH = TWIS_IER_SAM, TWIS_INTERRUPT_GENCALL_MATCH = TWIS_IER_GCM, TWIS_INTERRUPT_SMBUS_HHADR_MATCH = TWIS_IER_SMBHHM, TWIS_INTERRUPT_SMBUS_DEFADR_MATCH = TWIS_IER_SMBDAM, TWIS_INTERRUPT_STOP_RECEIVED = TWIS_IER_STO, TWIS_INTERRUPT_RESTART_RECEIVED = TWIS_IER_REP, TWIS_INTERRUPT_BYTE_TRANS_FINISHED = TWIS_IER_BTF, TWIS_INTERRUPT_ERRORS, TWIS_INTERRUPT_ALL = ~0UL }
	TWIS interrupt source type. More...

Functions
static void	twis_clear_status (struct twis_dev_inst *const dev_inst, uint32_t clear_status)
	Clear the current status of the TWIS. More...

void	twis_disable (struct twis_dev_inst *const dev_inst)
	Disable TWIS Module. More...

static void	twis_disable_interrupt (struct twis_dev_inst *const dev_inst, twis_interrupt_source_t interrupt_source)
	Disable the TWIS interrupts. More...

void	twis_enable (struct twis_dev_inst *const dev_inst)
	Enable TWIS Module. More...

static void	twis_enable_interrupt (struct twis_dev_inst *const dev_inst, twis_interrupt_source_t interrupt_source)
	Enable the TWIS interrupts. More...

void	twis_get_config_defaults (struct twis_config *const cfg)
	Get the TWIS master default configurations. More...

static uint32_t	twis_get_interrupt_mask (struct twis_dev_inst *const dev_inst)
	Get the TWIS interrupt mask. More...

static uint8_t	twis_get_smbus_pec (struct twis_dev_inst *const dev_inst)
	Get the calculated PEC value. More...

static uint8_t	twis_get_smbus_transfer_nb (struct twis_dev_inst *const dev_inst)
	Get the progress of the transfer in SMBus mode. More...

static uint32_t	twis_get_status (struct twis_dev_inst *const dev_inst)
	Information about the current status of the TWIS. More...

enum status_code	twis_init (struct twis_dev_inst const dev_inst, Twis const twis, struct twis_config *config)
	Initialize the TWI Slave Module. More...

static enum status_code	twis_read (struct twis_dev_inst const dev_inst, uint8_t data)
	Get the last byte data received from TWI bus. More...

static void	twis_send_data_ack (struct twis_dev_inst *const dev_inst)
	Enable ACK transfer in Slave Receiver Mode. More...

static void	twis_send_data_nack (struct twis_dev_inst *const dev_inst)
	Enable NACK transfer in Slave Receiver Mode. More...

void	twis_set_callback (struct twis_dev_inst *const dev_inst, twis_interrupt_source_t source, twis_callback_t callback, uint8_t irq_level)
	Set callback for TWIS. More...

static void	twis_set_smbus_transfer_nb (struct twis_dev_inst *const dev_inst, uint8_t nb, bool increment)
	Set the total number of data bytes in the transmission. More...

static enum status_code	twis_write (struct twis_dev_inst *const dev_inst, uint8_t byte)
	Write one byte data to TWI bus. More...

#define TWIS_WAIT_TIMEOUT 1000

Referenced by twis_read(), and twis_write().

typedef struct twis_callback twis_callback_t

typedef enum twis_interrupt_source twis_interrupt_source_t

TWIS interrupt source type.

enum twis_interrupt_source

TWIS interrupt source type.

Enumerator
TWIS_INTERRUPT_RX_BUFFER_READY
TWIS_INTERRUPT_TX_BUFFER_READY
TWIS_INTERRUPT_TRANS_COMP
TWIS_INTERRUPT_UNDER_RUN
TWIS_INTERRUPT_OVER_RUN
TWIS_INTERRUPT_NAK_RECEIVED
TWIS_INTERRUPT_SMBUS_TIMEOUT
TWIS_INTERRUPT_SMBUS_PEC_ERROR
TWIS_INTERRUPT_BUS_ERROR
TWIS_INTERRUPT_SLAVEADR_MATCH
TWIS_INTERRUPT_GENCALL_MATCH
TWIS_INTERRUPT_SMBUS_HHADR_MATCH
TWIS_INTERRUPT_SMBUS_DEFADR_MATCH
TWIS_INTERRUPT_STOP_RECEIVED
TWIS_INTERRUPT_RESTART_RECEIVED
TWIS_INTERRUPT_BYTE_TRANS_FINISHED
TWIS_INTERRUPT_ERRORS
TWIS_INTERRUPT_ALL

static void twis_clear_status	(	struct twis_dev_inst *const	dev_inst,
		uint32_t	clear_status
	)

inlinestatic

Clear the current status of the TWIS.

Parameters

dev_inst	Device structure pointer
clear_status	The TWIS status to be clear

References Assert, and twis_dev_inst::hw_dev.

Referenced by twis_interrupt_handler().

void twis_disable ( struct twis_dev_inst *const dev_inst )

Disable TWIS Module.

Parameters

dev_inst Device structure pointer

References Assert, twis_dev_inst::hw_dev, SLEEPMGR_SLEEP_1, and sleepmgr_unlock_mode().

static void twis_disable_interrupt	(	struct twis_dev_inst *const	dev_inst,
		twis_interrupt_source_t	interrupt_source
	)

inlinestatic

Disable the TWIS interrupts.

Parameters

dev_inst	Device structure pointer.
interrupt_source	The TWIS interrupt to be disabled

References Assert, and twis_dev_inst::hw_dev.

Referenced by twis_interrupt_handler().

void twis_enable ( struct twis_dev_inst *const dev_inst )

Enable TWIS Module.

Parameters

dev_inst Device structure pointer

References Assert, twis_dev_inst::hw_dev, sleepmgr_lock_mode(), and SLEEPMGR_SLEEP_1.

Referenced by main().

static void twis_enable_interrupt	(	struct twis_dev_inst *const	dev_inst,
		twis_interrupt_source_t	interrupt_source
	)

inlinestatic

Enable the TWIS interrupts.

Parameters

dev_inst	Device structure pointer
interrupt_source	The TWIS interrupt source to be enabled

References Assert, and twis_dev_inst::hw_dev.

Referenced by twis_interrupt_handler(), and twis_set_callback().

void twis_get_config_defaults ( struct twis_config *const cfg )

Get the TWIS master default configurations.

Use to initialize the configuration structure to known default values. This function should be called at the start of any TWIS initiation.

The default configuration is as follows:

7-bit addressing
Self address is 0x50.
Normal mode
Do not stretch clock on data byte reception
Do not stretch clock on address match
Stretch clock if RHR is full or THR is empty
Do not acknowledge the general call address
Acknowledge the specified slave address
Disable packet error checking
Do not acknowledge the SMBus host header
Do not acknowledge the SMBus default address
0 data setup cycles in F/S mode and high speed mode
Zero-initialization for slew rate setting in F/S mode and high speed mode
Clock Prescaler is 0
0 SMBus TIMEOUT cycle
0 SMBus Low:Sext cycle

Parameters

cfg	Pointer to configuration structure to be initiated.

References twis_config::ack_general_call, twis_config::ack_slave_addr, twis_config::ack_smbus_default_addr, twis_config::ack_smbus_host_header, Assert, twis_config::chip, twis_config::enable_pec, twis_config::exp, twis_config::fs_dadrivel, twis_config::fs_daslew, twis_config::fs_filter, twis_config::hddat, twis_config::hs_dadrivel, twis_config::hs_daslew, twis_config::hs_filter, twis_config::smbus, twis_config::stretch_clk_addr, twis_config::stretch_clk_data, twis_config::stretch_clk_hr, twis_config::sudat, twis_config::ten_bit, twis_config::tlows, and twis_config::ttouts.

Referenced by main().

static uint32_t twis_get_interrupt_mask ( struct twis_dev_inst *const dev_inst )

inlinestatic

Get the TWIS interrupt mask.

Parameters

dev_inst Device structure pointer.

Return values

TWIS	interrupt mask

References Assert, and twis_dev_inst::hw_dev.

Referenced by twis_interrupt_handler().

static uint8_t twis_get_smbus_pec ( struct twis_dev_inst *const dev_inst )

inlinestatic

Get the calculated PEC value.

Only for SMBus mode.

Parameters

dev_inst Device structure pointer.

Return values

Calculated PEC value

References Assert, and twis_dev_inst::hw_dev.

static uint8_t twis_get_smbus_transfer_nb ( struct twis_dev_inst *const dev_inst )

inlinestatic

Get the progress of the transfer in SMBus mode.

Parameters

dev_inst Device structure pointer.

Return values

The	left number of data bytes in the transmission.

References Assert, and twis_dev_inst::hw_dev.

static uint32_t twis_get_status ( struct twis_dev_inst *const dev_inst )

inlinestatic

Information about the current status of the TWIS.

Parameters

dev_inst Device structure pointer.

References Assert, and twis_dev_inst::hw_dev.

Referenced by twis_interrupt_handler().

enum status_code twis_init	(	struct twis_dev_inst *const	dev_inst,
		Twis *const	twis,
		struct twis_config *	config
	)

Initialize the TWI Slave Module.

Parameters

dev_inst	Device structure pointer
twis	Base address of the TWIS
config	Configuration for the TWIS

Returns: Status of module initialization.

Return values

STATUS_OK	The data is written correctly.
STATUS_ERR_DENIED	Initialization failed due to the module was enable before.
STATUS_ERR_BUSY	Initialization failed due to the module is busy with transfer.

References Assert, twis_dev_inst::hw_dev, STATUS_ERR_BUSY, STATUS_ERR_DENIED, STATUS_OK, sysclk_enable_peripheral_clock(), twis_find_ch_num(), and twis_set_config().

Referenced by main().

static enum status_code twis_read	(	struct twis_dev_inst *const	dev_inst,
		uint8_t *	data
	)

inlinestatic

Get the last byte data received from TWI bus.

Parameters

dev_inst	Device structure pointer.
*data	The read data.

Returns: Status of write operation.

Return values

STATUS_OK	The data is read correctly.
STATUS_ERR_TIMEOUT	The read operation aborted due to timeout.

References Assert, twis_dev_inst::hw_dev, STATUS_ERR_TIMEOUT, STATUS_OK, and TWIS_WAIT_TIMEOUT.

static void twis_send_data_ack ( struct twis_dev_inst *const dev_inst )

inlinestatic

Enable ACK transfer in Slave Receiver Mode.

Parameters

dev_inst Device structure pointer.

References Assert, and twis_dev_inst::hw_dev.

static void twis_send_data_nack ( struct twis_dev_inst *const dev_inst )

inlinestatic

Enable NACK transfer in Slave Receiver Mode.

Parameters

dev_inst Device structure pointer.

References Assert, and twis_dev_inst::hw_dev.

void twis_set_callback	(	struct twis_dev_inst *const	dev_inst,
		twis_interrupt_source_t	source,
		twis_callback_t	callback,
		uint8_t	irq_level
	)

Set callback for TWIS.

Note: Slave address match interrupt is enabled in default so that TWIS ISR can work appropriately.

Parameters

dev_inst	Device structure pointer
source	Interrupt source
callback	Callback function pointer
irq_level	Interrupt level

References Assert, twis_dev_inst::hw_dev, irq_register_handler, twis_enable_interrupt(), twis_find_ch_num(), and TWIS_INTERRUPT_SLAVEADR_MATCH.

Referenced by main().

static void twis_set_smbus_transfer_nb	(	struct twis_dev_inst *const	dev_inst,
		uint8_t	nb,
		bool	increment
	)

inlinestatic

Set the total number of data bytes in the transmission.

Only for SMBus mode.

Parameters

dev_inst	Device structure pointer
nb	Total number of data bytes in the transmission
increment	Count up per byte transferred if true, otherwise count down

References Assert, and twis_dev_inst::hw_dev.

static enum status_code twis_write	(	struct twis_dev_inst *const	dev_inst,
		uint8_t	byte
	)

inlinestatic

Write one byte data to TWI bus.

Parameters

dev_inst	Device structure pointer.
byte	The byte data to write.

Returns: Status of write operation.

Return values

STATUS_OK	The data is written correctly.
STATUS_ERR_TIMEOUT	The write operation aborted due to timeout.

References Assert, twis_dev_inst::hw_dev, STATUS_ERR_TIMEOUT, STATUS_OK, and TWIS_WAIT_TIMEOUT.

Microchip® Advanced Software Framework

Data Structures

Macros

Typedefs

Enumerations

Functions