TWI::Client Class Reference

Base abstract definition for a TWI client. This class implements the basic state machine to interface a TWI bus as a client. It is design to be controlled by a upper layer object (a controller). The interface notifies the controller of bus events (start, address, etc) via the signals and the controller shall use the API of this class to react accordingly. More...

#include <sim_twi.h>

Inheritance diagram for TWI::Client:

Public Types
enum	State {   State_Disabled = 0 , State_Idle , State_Start , State_AddressRx ,   State_AddressRAck , State_AddressWAck , State_DataTx , State_DataTxAck ,   State_DataRx , State_DataRxAck , State_Count }

Public Member Functions
	Client ()
void	init (CycleManager &cycle_manager)
State	state () const
void	set_enabled (bool enabled)
bool	enabled () const
void	reset ()
bool	active () const
bool	clock_hold () const
unsigned char	rw () const
bool	ack () const
bool	set_ack (bool ack)
bool	start_data_tx (uint8_t data)
bool	start_data_rx ()
Signal &	signal ()
virtual cycle_count_t	next (cycle_count_t when) override
	Callback from the cycle loop.
Public Member Functions inherited from TWI::EndPoint
	EndPoint ()
virtual	~EndPoint ()=default
void	line_state_changed (TWI::Line line, bool dig_state)
bool	get_clock_drive () const
bool	get_data_drive () const
Public Member Functions inherited from CycleTimer
	CycleTimer ()
	CycleTimer (const CycleTimer &other)
virtual	~CycleTimer ()
bool	scheduled () const
	Returns true if this timer is scheduled with a manager.
bool	paused () const
cycle_count_t	remaining_delay () const
CycleTimer &	operator= (const CycleTimer &other)

Protected Member Functions
virtual void	clock_level_changed (bool level) override
virtual void	data_level_changed (bool level) override
Protected Member Functions inherited from TWI::EndPoint
virtual void	set_line_state (TWI::Line line, bool dig_state)=0
void	set_clock_drive (bool level)
bool	get_clock_level () const
void	set_data_drive (bool level)
bool	get_data_level () const

Detailed Description

Base abstract definition for a TWI client. This class implements the basic state machine to interface a TWI bus as a client. It is design to be controlled by a upper layer object (a controller). The interface notifies the controller of bus events (start, address, etc) via the signals and the controller shall use the API of this class to react accordingly.

See also

TWI, EndPoint, Host

Member Enumeration Documentation

State

enum TWI::Client::State

Enumerator
State_Disabled	Client disabled
State_Idle	Client idle
State_Start	Receiving a Start condition.
State_AddressRx	Receving a Address/RW byte.
State_AddressRAck	Pending/transmitting a ACK/NACK for a read request.
State_AddressWAck	Pending/transmitting a ACK/NACK for a Write request.
State_DataTx	Read request ACKed, in TX mode, pending/transmitting data.
State_DataTxAck	Data sent, receiving ACK bit from the host.
State_DataRx	Write request ACKed, in RX mode, pending/receiving data.
State_DataRxAck	Data received, pending/sending ACK bit.
State_Count	Total number of states.

Constructor & Destructor Documentation

Client()

Client::Client

(

)

Member Function Documentation

ack()

bool TWI::Client::ack ( ) const

inline

Returns the latest state of the ACK bit, either sent by this client, or received by the host, after an address or a data byte.

Returns

true for ACK, false for NACK

active()

bool Client::active

(

)

const

Returns whether the interface is currently active, i.e. participating in bus traffic. For a client, it means it has positively acknowledged the address byte.

clock_hold()

bool Client::clock_hold

(

)

const

Returns whether the client is currently holding the clock line.

clock_level_changed()

void Client::clock_level_changed ( bool  level )

overrideprotectedvirtual

Implements TWI::EndPoint.

data_level_changed()

void Client::data_level_changed ( bool  level )

overrideprotectedvirtual

Implements TWI::EndPoint.

enabled()

bool TWI::Client::enabled ( ) const

inline

Returns true if the client is enabled, false if disabled.

init()

void Client::init

(

CycleManager &

manager

)

Initialisation of the interface, must be called before any operation.

next()

cycle_count_t Client::next ( cycle_count_t  when )

overridevirtual

Callback from the cycle loop.

Note

there's no guarantee the method will be called exactly on the required 'when' cycle. The only guarantee is "called 'when' <= 'current cycle'", the implementations must account for this.

Parameters

when	current 'when' cycle, at which the timer was scheduled

Returns

the next 'when' the timer requires to be called at.

Note

The next 'when' can be in the 'past' (i.e. <= 'current cycle'). In this case, the timer will be called again within the same cycle with the given next 'when'. The only constraint is that it must be greater than the previous 'when'. If it's negative or zero, the timer is removed from the queue.

Implements CycleTimer.

reset()

void Client::reset

(

)

Reset the interface to the Idle state. No-op if the interface is disabled.

rw()

unsigned char Client::rw

(

)

const

Returns the direction of the current request, depending on the latest RW bit received.

Returns

1 for a Read Request, 0 for a Write Request

set_ack()

bool Client::set_ack

(

bool

ack

)

Set the ack reply, after either an address or a data byte has been received.

Parameters

ack	true for ACK, false for NACK

Returns

true if the call was 'legal' i.e. the host was waiting for a ACK, false otherwise

set_enabled()

void Client::set_enabled

(

bool

enabled

)

Enable/disable the interface.

signal()

Signal & TWI::Client::signal ( )

inline

Getter for the client signal.

start_data_rx()

bool Client::start_data_rx

(

)

Start receiving a data byte, in response to a Write Request.

Returns

true if the call was 'legal', false otherwise

start_data_tx()

bool Client::start_data_tx

(

uint8_t

data

)

Start transmitting a data byte, in response to a Read Request.

Parameters

data	byte to be transmitted

Returns

true if the call was 'legal', false otherwise

state()

Client::State TWI::Client::state ( ) const

inline

Getter for the state of the client.

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The documentation for this class was generated from the following files:

• sim_twi.h
• sim_twi.cpp