Mistake on this page?
Report an issue in GitHub or email us
Public Member Functions | Static Public Member Functions
I2CEEBlockDevice Class Referenceabstract

BlockDevice for I2C based flash device such as Microchip's 24LC or ATMEL's AT24C ranges. More...

#include <I2CEEBlockDevice.h>

Inheritance diagram for I2CEEBlockDevice:
BlockDevice

Public Member Functions

 I2CEEBlockDevice (PinName sda, PinName scl, uint8_t address, bd_size_t size, bd_size_t block=32, int bus_speed=400000, bool address_is_eight_bit=false)
 Constructor to create an I2CEEBlockDevice on I2C pins. More...
 
 I2CEEBlockDevice (mbed::I2C *i2c_obj, uint8_t address, bd_size_t size, bd_size_t block=32, bool address_is_eight_bit=false)
 Constructor to create an I2CEEBlockDevice on I2C pins. More...
 
virtual ~I2CEEBlockDevice ()
 Destructor of I2CEEBlockDevice. More...
 
virtual int init ()
 Initialize a block device. More...
 
virtual int deinit ()
 Deinitialize a block device. More...
 
virtual int read (void *buffer, bd_addr_t addr, bd_size_t size)
 Read blocks from a block device. More...
 
virtual int program (const void *buffer, bd_addr_t addr, bd_size_t size)
 Program blocks to a block device. More...
 
virtual int erase (bd_addr_t addr, bd_size_t size)
 Erase blocks on a block device. More...
 
virtual bd_size_t get_read_size () const
 Get the size of a readable block. More...
 
virtual bd_size_t get_program_size () const
 Get the size of a programable block. More...
 
virtual bd_size_t get_erase_size () const
 Get the size of a eraseable block. More...
 
virtual bd_size_t size () const
 Get the total size of the underlying device. More...
 
virtual const char * get_type () const
 Get the BlockDevice class type. More...
 
virtual int sync ()
 Ensure data on storage is in sync with the driver. More...
 
virtual int read (void *buffer, bd_addr_t addr, bd_size_t size)=0
 Read blocks from a block device. More...
 
virtual int program (const void *buffer, bd_addr_t addr, bd_size_t size)=0
 Program blocks to a block device. More...
 
virtual int erase (bd_addr_t addr, bd_size_t size)
 Erase blocks on a block device. More...
 
virtual int trim (bd_addr_t addr, bd_size_t size)
 Mark blocks as no longer in use. More...
 
virtual bd_size_t get_erase_size (bd_addr_t addr) const
 Get the size of an erasable block given address. More...
 
virtual int get_erase_value () const
 Get the value of storage when erased. More...
 
virtual bool is_valid_read (bd_addr_t addr, bd_size_t size) const
 Convenience function for checking block read validity. More...
 
virtual bool is_valid_program (bd_addr_t addr, bd_size_t size) const
 Convenience function for checking block program validity. More...
 
virtual bool is_valid_erase (bd_addr_t addr, bd_size_t size) const
 Convenience function for checking block erase validity. More...
 

Static Public Member Functions

static BlockDeviceget_default_instance ()
 Return the default block device. More...
 

Detailed Description

BlockDevice for I2C based flash device such as Microchip's 24LC or ATMEL's AT24C ranges.

// Here's an example using a 24LC256 on a GR PEACH
#include "mbed.h"
#include "I2CEEBlockDevice.h"
// Create EEPROM device on I2C bus with 32kbytes of memory
I2CEEBlockDevice i2cee(D14, D15, 0xa0, 32*1024);
int main() {
printf("i2cee test\n");
// Initialize the device and print the memory layout
i2cee.init();
printf("i2cee size: %llu\n", i2cee.size());
printf("i2cee read size: %llu\n", i2cee.get_read_size());
printf("i2cee program size: %llu\n", i2cee.get_program_size());
printf("i2cee erase size: %llu\n", i2cee.get_erase_size());
// Write "Hello World!" to the first block
char *buffer = (char*)malloc(i2cee.get_erase_size());
sprintf(buffer, "Hello World!\n");
i2cee.erase(0, i2cee.get_erase_size());
i2cee.program(buffer, 0, i2cee.get_erase_size());
// Read back what was stored
i2cee.read(buffer, 0, i2cee.get_erase_size());
printf("%s", buffer);
// Deinitialize the device
i2cee.deinit();
}

Definition at line 59 of file I2CEEBlockDevice.h.

Constructor & Destructor Documentation

I2CEEBlockDevice ( PinName  sda,
PinName  scl,
uint8_t  address,
bd_size_t  size,
bd_size_t  block = 32,
int  bus_speed = 400000,
bool  address_is_eight_bit = false 
)

Constructor to create an I2CEEBlockDevice on I2C pins.

Parameters
sdaThe pin name for the sda line of the I2C bus.
sclThe pin name for the scl line of the I2C bus.
addrThe 8bit I2C address of the chip, common range 0xa0 - 0xae.
sizeThe size of the device in bytes
blockThe page size of the device in bytes, defaults to 32bytes
freqThe frequency of the I2C bus, defaults to 400K.
address_is_eight_bitSpecifies whether the EEPROM device is using eight bit addresses instead of 16 bit addresses. This is used for example in AT24C series chips.
I2CEEBlockDevice ( mbed::I2C i2c_obj,
uint8_t  address,
bd_size_t  size,
bd_size_t  block = 32,
bool  address_is_eight_bit = false 
)

Constructor to create an I2CEEBlockDevice on I2C pins.

Parameters
i2cThe I2C instance pointer
addrThe 8bit I2C address of the chip, common range 0xa0 - 0xae.
sizeThe size of the device in bytes
blockThe page size of the device in bytes, defaults to 32bytes
freqThe frequency of the I2C bus, defaults to 400K.
address_is_eight_bitSpecifies whether the EEPROM device is using eight bit addresses instead of 16 bit addresses. This is used for example in AT24C series chips.
virtual ~I2CEEBlockDevice ( )
virtual

Destructor of I2CEEBlockDevice.

Member Function Documentation

virtual int deinit ( )
virtual

Deinitialize a block device.

Returns
0 on success or a negative error code on failure

Implements BlockDevice.

virtual int erase ( bd_addr_t  addr,
bd_size_t  size 
)
virtualinherited

Erase blocks on a block device.

The state of an erased block is undefined until it has been programmed, unless get_erase_value returns a non-negative byte value

Parameters
addrAddress of block to begin erasing
sizeSize to erase in bytes, must be a multiple of the erase block size
Returns
0 on success or a negative error code on failure

Reimplemented in OSPIFBlockDevice, QSPIFBlockDevice, SPIFBlockDevice, MBRBlockDevice, DataFlashBlockDevice, ChainingBlockDevice, HeapBlockDevice, ExhaustibleBlockDevice, SlicingBlockDevice, FlashSimBlockDevice, ObservingBlockDevice, ProfilingBlockDevice, BufferedBlockDevice, ReadOnlyBlockDevice, and FlashIAPBlockDevice.

Definition at line 121 of file BlockDevice.h.

virtual int erase ( bd_addr_t  addr,
bd_size_t  size 
)
virtual

Erase blocks on a block device.

The state of an erased block is undefined until it has been programmed

Parameters
addrAddress of block to begin erasing
sizeSize to erase in bytes, must be a multiple of erase block size
Returns
0 on success, negative error code on failure
static BlockDevice* get_default_instance ( )
staticinherited

Return the default block device.

Returns the default block device based on the configuration JSON. Use the components in target.json or application config to change the default block device.

An application can override all target settings by implementing BlockDevice::get_default_instance() - the default definition is weak, and calls get_target_default_instance().

virtual bd_size_t get_erase_size ( ) const
virtual

Get the size of a eraseable block.

Returns
Size of a eraseable block in bytes
Note
Must be a multiple of the program size

Reimplemented from BlockDevice.

virtual bd_size_t get_erase_size ( bd_addr_t  addr) const
virtualinherited

Get the size of an erasable block given address.

Parameters
addrAddress within the erasable block
Returns
Size of an erasable block in bytes
Note
Must be a multiple of the program size

Reimplemented in QSPIFBlockDevice, SPIFBlockDevice, MBRBlockDevice, DataFlashBlockDevice, ChainingBlockDevice, HeapBlockDevice, BufferedBlockDevice, ExhaustibleBlockDevice, SlicingBlockDevice, FlashSimBlockDevice, ProfilingBlockDevice, ObservingBlockDevice, ReadOnlyBlockDevice, and FlashIAPBlockDevice.

Definition at line 171 of file BlockDevice.h.

virtual int get_erase_value ( ) const
virtualinherited

Get the value of storage when erased.

If get_erase_value returns a non-negative byte value, the underlying storage is set to that value when erased, and storage containing that value can be programmed without another erase.

Returns
The value of storage when erased, or -1 if you can't rely on the value of the erased storage

Reimplemented in OSPIFBlockDevice, QSPIFBlockDevice, SPIFBlockDevice, MBRBlockDevice, ChainingBlockDevice, BufferedBlockDevice, ExhaustibleBlockDevice, SlicingBlockDevice, ProfilingBlockDevice, ObservingBlockDevice, FlashSimBlockDevice, ReadOnlyBlockDevice, and FlashIAPBlockDevice.

Definition at line 185 of file BlockDevice.h.

virtual bd_size_t get_program_size ( ) const
virtual

Get the size of a programable block.

Returns
Size of a programable block in bytes
Note
Must be a multiple of the read size

Implements BlockDevice.

virtual bd_size_t get_read_size ( ) const
virtual

Get the size of a readable block.

Returns
Size of a readable block in bytes

Implements BlockDevice.

virtual const char* get_type ( ) const
virtual

Get the BlockDevice class type.

Returns
A string representation of the BlockDevice class type.

Implements BlockDevice.

virtual int init ( )
virtual

Initialize a block device.

Returns
0 on success or a negative error code on failure

Implements BlockDevice.

virtual bool is_valid_erase ( bd_addr_t  addr,
bd_size_t  size 
) const
virtualinherited

Convenience function for checking block erase validity.

Parameters
addrAddress of block to begin erasing
sizeSize to erase in bytes
Returns
True if erase is valid for underlying block device

Reimplemented in SlicingBlockDevice.

Definition at line 230 of file BlockDevice.h.

virtual bool is_valid_program ( bd_addr_t  addr,
bd_size_t  size 
) const
virtualinherited

Convenience function for checking block program validity.

Parameters
addrAddress of block to begin writing to
sizeSize to write in bytes
Returns
True if program is valid for underlying block device

Reimplemented in SlicingBlockDevice.

Definition at line 216 of file BlockDevice.h.

virtual bool is_valid_read ( bd_addr_t  addr,
bd_size_t  size 
) const
virtualinherited

Convenience function for checking block read validity.

Parameters
addrAddress of block to begin reading from
sizeSize to read in bytes
Returns
True if read is valid for underlying block device

Reimplemented in SlicingBlockDevice.

Definition at line 202 of file BlockDevice.h.

virtual int program ( const void *  buffer,
bd_addr_t  addr,
bd_size_t  size 
)
pure virtualinherited

Program blocks to a block device.

The blocks must have been erased prior to being programmed

If a failure occurs, it is not possible to determine how many bytes succeeded

Parameters
bufferBuffer of data to write to blocks
addrAddress of block to begin writing to
sizeSize to write in bytes, must be a multiple of the program block size
Returns
0 on success or a negative error code on failure

Implemented in OSPIFBlockDevice, QSPIFBlockDevice, SPIFBlockDevice, SDBlockDevice, MBRBlockDevice, DataFlashBlockDevice, ChainingBlockDevice, HeapBlockDevice, ExhaustibleBlockDevice, SlicingBlockDevice, FlashSimBlockDevice, ObservingBlockDevice, ProfilingBlockDevice, BufferedBlockDevice, ReadOnlyBlockDevice, and FlashIAPBlockDevice.

virtual int program ( const void *  buffer,
bd_addr_t  addr,
bd_size_t  size 
)
virtual

Program blocks to a block device.

The blocks must have been erased prior to being programmed

Parameters
bufferBuffer of data to write to blocks
addrAddress of block to begin writing to
sizeSize to write in bytes, must be a multiple of program block size
Returns
0 on success, negative error code on failure
virtual int read ( void *  buffer,
bd_addr_t  addr,
bd_size_t  size 
)
pure virtualinherited

Read blocks from a block device.

If a failure occurs, it is not possible to determine how many bytes succeeded

Parameters
bufferBuffer to write blocks to
addrAddress of block to begin reading from
sizeSize to read in bytes, must be a multiple of the read block size
Returns
0 on success or a negative error code on failure

Implemented in OSPIFBlockDevice, QSPIFBlockDevice, SPIFBlockDevice, MBRBlockDevice, DataFlashBlockDevice, SDBlockDevice, ChainingBlockDevice, HeapBlockDevice, ExhaustibleBlockDevice, SlicingBlockDevice, FlashSimBlockDevice, ObservingBlockDevice, ProfilingBlockDevice, BufferedBlockDevice, ReadOnlyBlockDevice, and FlashIAPBlockDevice.

virtual int read ( void *  buffer,
bd_addr_t  addr,
bd_size_t  size 
)
virtual

Read blocks from a block device.

Parameters
bufferBuffer to write blocks to
addrAddress of block to begin reading from
sizeSize to read in bytes, must be a multiple of read block size
Returns
0 on success, negative error code on failure
virtual bd_size_t size ( ) const
virtual

Get the total size of the underlying device.

Returns
Size of the underlying device in bytes

Implements BlockDevice.

virtual int sync ( )
virtualinherited

Ensure data on storage is in sync with the driver.

Returns
0 on success or a negative error code on failure

Reimplemented in MBRBlockDevice, ChainingBlockDevice, ExhaustibleBlockDevice, SlicingBlockDevice, FlashSimBlockDevice, ObservingBlockDevice, ProfilingBlockDevice, BufferedBlockDevice, and ReadOnlyBlockDevice.

Definition at line 83 of file BlockDevice.h.

virtual int trim ( bd_addr_t  addr,
bd_size_t  size 
)
virtualinherited

Mark blocks as no longer in use.

This function provides a hint to the underlying block device that a region of blocks is no longer in use and may be erased without side effects. Erase must still be called before programming, but trimming allows flash-translation-layers to schedule erases when the device is not busy.

Parameters
addrAddress of block to mark as unused
sizeSize to mark as unused in bytes, must be a multiple of the erase block size
Returns
0 on success or a negative error code on failure

Reimplemented in SDBlockDevice, and BufferedBlockDevice.

Definition at line 137 of file BlockDevice.h.

Important Information for this Arm website

This site uses cookies to store information on your computer. By continuing to use our site, you consent to our cookies. If you are not happy with the use of these cookies, please review our Cookie Policy to learn how they can be disabled. By disabling cookies, some features of the site will not work.