EEPROMClass Class Reference

26 bytes of emulated EEPROM in the option-byte area, worked on in a RAM copy and written by commit() (see EEPROM). More...

#include <EEPROM.h>

Public Member Functions
	EEPROMClass (void)
	Makes the object; nothing is read until begin().
	~EEPROMClass (void)
	Calls end(), which commits any change.
void	begin (void)
	Copies the 26 bytes from the option-byte area into RAM (26 bytes on the heap, allocated the first time).
uint8_t *	getDataPtr ()
	The 26-byte RAM copy, to change in place; marks it changed, so the next commit() writes it.
uint8_t const *	getConstDataPtr () const
	The 26-byte RAM copy, read-only.
uint32_t	ReadOptionBytes (void)
	Reads the option bytes Data0 and Data1 straight from the chip (no begin() needed).
uint8_t	read (int const idx)
	Reads a byte of the RAM copy.
void	write (int const idx, uint8_t const val)
	Changes a byte of the RAM copy; commit() writes it.
void	erase (void)
	Sets the 26 bytes of the RAM copy to 0xFF; commit() writes them.
bool	commit (void)
	Writes the RAM copy to the option-byte area, if anything changed since begin() or the last commit().
bool	end (void)
	Commits, then forgets the RAM copy (its 26 bytes are not freed); begin() starts again.
template<typename T >
T &	get (int const address, T &t)
	Copies sizeof(T) bytes of the RAM copy into t.
template<typename T >
const T &	put (int const address, const T &t)
	Copies t into the RAM copy, if it differs; commit() writes it.
size_t	length ()
	The emulated EEPROM's size.
uint8_t &	operator[] (int const address)
	A byte of the RAM copy, to read or change; marks the copy changed.
uint8_t const &	operator[] (int const address) const
	A byte of the RAM copy, read-only.

Protected Attributes
uint8_t *	_data = nullptr
	The RAM copy (26 bytes after begin()).
bool	_dirty = false
	Whether the copy changed since begin() or the last commit().
size_t	_size = 0
	The copy's size: 26 after begin(), else 0.

Detailed Description

26 bytes of emulated EEPROM in the option-byte area, worked on in a RAM copy and written by commit() (see EEPROM).

Constructor & Destructor Documentation

EEPROMClass()

EEPROMClass::EEPROMClass

(

void

)

Makes the object; nothing is read until begin().

~EEPROMClass()

EEPROMClass::~EEPROMClass

(

void

)

Calls end(), which commits any change.

Member Function Documentation

begin()

void EEPROMClass::begin

(

void

)

Copies the 26 bytes from the option-byte area into RAM (26 bytes on the heap, allocated the first time).

Call it before anything else.

On the CH32X035 only bytes 0 and 1 (Data0, Data1) are read; bytes 2-25 start as 0xFF.

getDataPtr()

uint8_t * EEPROMClass::getDataPtr

(

)

The 26-byte RAM copy, to change in place; marks it changed, so the next commit() writes it.

Returns

the copy, or nullptr before begin().

getConstDataPtr()

uint8_t const * EEPROMClass::getConstDataPtr

(

)

const

The 26-byte RAM copy, read-only.

Returns

the copy, or nullptr before begin().

ReadOptionBytes()

uint32_t EEPROMClass::ReadOptionBytes

(

void

)

Reads the option bytes Data0 and Data1 straight from the chip (no begin() needed).

Returns

Data0's half-word in the high 16 bits and Data1's in the low 16; in each, the low byte is the value and the high byte its inverse.

read()

uint8_t EEPROMClass::read

(

int const

idx

)

Reads a byte of the RAM copy.

Parameters

idx

0 to 25.

Returns

the byte; 0 if idx is out of range or before begin().

write()

void EEPROMClass::write	(	int const	idx,
		uint8_t const	val
	)

Changes a byte of the RAM copy; commit() writes it.

Parameters

idx	0 to 25; anything else is ignored, as is a call before begin().
val	the new value.

erase()

void EEPROMClass::erase

(

void

)

Sets the 26 bytes of the RAM copy to 0xFF; commit() writes them.

commit()

bool EEPROMClass::commit

(

void

)

Writes the RAM copy to the option-byte area, if anything changed since begin() or the last commit().

Erases the whole area and rewrites it (see EEPROM). On the CH32X035 it writes nothing.

Returns

true if nothing had changed, or (CH32V003) once written: what was written is not checked. false on the CH32X035 whenever there was something to write.

end()

bool EEPROMClass::end

(

void

)

Commits, then forgets the RAM copy (its 26 bytes are not freed); begin() starts again.

Returns

what commit() returned.

get()

template<typename T >

T & EEPROMClass::get ( int const  address, T &  t  )

inline

Copies sizeof(T) bytes of the RAM copy into t.

Template Parameters

T	any plain type or struct.

Parameters

address	the first byte, 0 to 26 - sizeof(T).
t	receives the bytes; left as it was if they would not fit.

Returns

t.

put()

template<typename T >

const T & EEPROMClass::put ( int const  address, const T &  t  )

inline

Copies t into the RAM copy, if it differs; commit() writes it.

Template Parameters

T	any plain type or struct.

Parameters

address	the first byte, 0 to 26 - sizeof(T); nothing is stored if t would not fit.
t	the value.

Returns

t.

length()

size_t EEPROMClass::length ( )

inline

The emulated EEPROM's size.

Returns

26 after begin(), 0 before.

operator[]() [1/2]

uint8_t & EEPROMClass::operator[] ( int const  address )

inline

A byte of the RAM copy, to read or change; marks the copy changed.

No range check: call begin() first and keep to 0-25.

Parameters

address

0 to 25.

Returns

the byte.

operator[]() [2/2]

uint8_t const & EEPROMClass::operator[] ( int const  address ) const

inline

A byte of the RAM copy, read-only.

No range check.

Parameters

address

0 to 25.

Returns

the byte.

Member Data Documentation

_data

uint8_t* EEPROMClass::_data = nullptr

protected

The RAM copy (26 bytes after begin()).

_dirty

bool EEPROMClass::_dirty = false

protected

Whether the copy changed since begin() or the last commit().

_size

size_t EEPROMClass::_size = 0

protected

The copy's size: 26 after begin(), else 0.

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

• EEPROM/src/EEPROM.h