Selects one of two chips using a single pin. More...

#include <ChipBinarySelectManager.hpp>

Inheritance diagram for duds::hardware::interface::ChipBinarySelectManager:

Collaboration diagram for duds::hardware::interface::ChipBinarySelectManager:

Public Member Functions
	ChipBinarySelectManager ()
	Default constructor. More...

	ChipBinarySelectManager (std::unique_ptr< DigitalPinAccess > &&dpa, int initSel=0)
	Constructs a ChipBinarySelectManager with a pin for selection. More...

	~ChipBinarySelectManager ()
	Calls shutdown(). More...

void	setSelectPin (std::unique_ptr< DigitalPinAccess > &&dpa, int initSel=0)
	Sets the DigitalPinAccess object to use for the chip select line. More...

virtual bool	validChip (int chipId) const noexcept
	The only valid chip IDs for this manager are 0 and 1, and they are only valid once a DigitalPinAccess object has been provided. More...

Public Member Functions inherited from duds::hardware::interface::ChipSelectManager
	ChipSelectManager ()

virtual	~ChipSelectManager ()=0
	Derived non-abstract classes must call shutdown() in thier destructor. More...

std::unique_ptr< ChipAccess >	access (int chipId)
	Acquires access to the requested chip and issues a ChipAccess object. More...

void	access (ChipAccess &acc, int chipId)
	Acquires access to the requested chip and modifies an existing ChipAccess object to provide that access. More...

bool	inUse () const
	Returns true if an access object provided by this manager exists. More...

std::unique_ptr< ChipAccess >	select (int chipId)
	Selects the requested chip and issues a ChipAccess object. More...

void	select (ChipAccess &acc, int chipId)
	Selects the requested chip and modifies a ChipAccess object to further control chip selection. More...

Protected Member Functions
virtual void	deselect ()
	Deselects the chip identified by cid. More...

virtual void	select ()
	Selects the chip identified by cid. More...

Protected Member Functions inherited from duds::hardware::interface::ChipSelectManager
void	baseAccess (std::unique_lock< std::mutex > &lock, int chipId)
	Obtains the resources for providing an access object, but does not make an access object. More...

void	changeChip (int chipId)
	Changes the chip in use while continuing to use an existing access object. More...

void	shutdown ()
	Waits on a ChipAccess object if one is in use, then begins forcing any threads waiting on access to wake up and throw exceptions. More...

Private Attributes
std::unique_ptr< DigitalPinAccess >	selpin
	The access object for the select pin. More...

Additional Inherited Members
Protected Attributes inherited from duds::hardware::interface::ChipSelectManager
std::mutex	block
	Used to synchonize access. More...

int	cid
	Selected chip ID, or -1 to terminate. More...

Detailed Description

Selects one of two chips using a single pin.

This means one of the chips will always be selected. Not all chips will function properly using this scheme. At least some EEPROM's have no problem with it. The hardware implementation may require an inverter. Chip ID 0 is selected with a logic low, and ID 1 with a logic high.

Even though a chip is always selected, an access object should always be requested prior to using either chip. This will ensure the correct chip is selected by a multi-threaded program, and will work properly if the chip selection implementation is changed.

The pin used for chip selection must support output. This class allows any output type, but will select the first output type supported in this order:

Todo:: Change select() and deselect() to ensure that the operations force a state change, at least momentarily, on the select line.

Author: Jeff Jackowski

Definition at line 39 of file ChipBinarySelectManager.hpp.

Constructor & Destructor Documentation

◆ ChipBinarySelectManager() [1/2]

duds::hardware::interface::ChipBinarySelectManager::ChipBinarySelectManager ( )

Default constructor.

Definition at line 73 of file ChipBinarySelectManager.cpp.

◆ ChipBinarySelectManager() [2/2]

duds::hardware::interface::ChipBinarySelectManager::ChipBinarySelectManager	(	std::unique_ptr< DigitalPinAccess > &&	dpa,
		int	initSel = `0`
	)

Constructs a ChipBinarySelectManager with a pin for selection.

Parameters

dpa	The access object for the select pin.
initSel	Non-zero to initially select ID 1 (logic high), or zero for ID 0 (logic low).

Exceptions

ChipSelectInUse	A ChipAccess object provided by this manager currently exists.
PinDoesNotExist	The DigitalPinAccess object does not provide access to any pin.
DigitalPinCannotOutputError	The pin cannot output.

Definition at line 75 of file ChipBinarySelectManager.cpp.

◆ ~ChipBinarySelectManager()

duds::hardware::interface::ChipBinarySelectManager::~ChipBinarySelectManager ( )

Calls shutdown().

Definition at line 81 of file ChipBinarySelectManager.cpp.

Member Function Documentation

◆ deselect()

void duds::hardware::interface::ChipBinarySelectManager::deselect ( )

protectedvirtual

Deselects the chip identified by cid.

If the chip is already deselected, it must remain deselected.

Note: There is no need for thread synchronization in this function.

Implements duds::hardware::interface::ChipSelectManager.

Definition at line 23 of file ChipBinarySelectManager.cpp.

◆ select()

void duds::hardware::interface::ChipBinarySelectManager::select ( )

protectedvirtual

Selects the chip identified by cid.

If the chip is already selected, it must remain selected.

Note: There is no need for thread synchronization in this function.

Implements duds::hardware::interface::ChipSelectManager.

Definition at line 19 of file ChipBinarySelectManager.cpp.

◆ setSelectPin()

void duds::hardware::interface::ChipBinarySelectManager::setSelectPin	(	std::unique_ptr< DigitalPinAccess > &&	dpa,
		int	initSel = `0`
	)

Sets the DigitalPinAccess object to use for the chip select line.

Parameters

dpa	The access object for the select pin.
initSel	The initially selected chip ID. Must be 0 or 1.

Exceptions

ChipSelectInUse	A ChipAccess object provided by this manager currently exists.
PinDoesNotExist	The DigitalPinAccess object does not provide access to any pin.
DigitalPinCannotOutputError	The pin cannot output.

Definition at line 27 of file ChipBinarySelectManager.cpp.

Referenced by ChipBinarySelectManager().