Files
file	ext-flash.c
	Driver for the LaunchPad Flash and the Sensortag WinBond W25X20CL/W25X40CL.

file	ext-flash.h
	Header file for the Sensortag/LaunchPad External Flash Driver.

Macros
#define	BLS_CODE_PROGRAM 0x02
	Page Program.

#define	BLS_CODE_READ 0x03
	Read Data.

#define	BLS_CODE_READ_STATUS 0x05
	Read Status Register.

#define	BLS_CODE_WRITE_ENABLE 0x06
	Write Enable.

#define	BLS_CODE_SECTOR_ERASE 0x20
	Sector Erase.

#define	BLS_CODE_MDID 0x90
	Manufacturer Device ID.

#define	BLS_CODE_PD 0xB9
	Power down.

#define	BLS_CODE_RPD 0xAB
	Release Power-Down.

#define	BLS_CODE_ERASE_4K 0x20
	Sector Erase.

#define	BLS_CODE_ERASE_ALL 0xC7
	Mass Erase.

#define	BLS_STATUS_BIT_BUSY 0x01
	Busy bit of the status register.

Functions
static void	select_on_bus (void)
	Clear external flash CSN line.

static void	deselect (void)
	Set external flash CSN line.

static bool	wait_ready (void)
	Wait till previous erase/program operation completes. More...

static uint8_t	verify_part (void)
	Verify the flash part. More...

static void	power_down (void)
	Put the device in power save mode. More...

static bool	power_standby (void)
	Take device out of power save mode and prepare it for normal operation. More...

static bool	write_enable (void)
	Enable write. More...

bool	ext_flash_open (void)
	Initialize storage driver. More...

void	ext_flash_close (void)
	Close the storage driver. More...

bool	ext_flash_read (size_t offset, size_t length, uint8_t *buf)
	Read storage content. More...

bool	ext_flash_write (size_t offset, size_t length, const uint8_t *buf)
	Write to storage sectors. More...

bool	ext_flash_erase (size_t offset, size_t length)
	Erase storage sectors corresponding to the range. More...

bool	ext_flash_test (void)
	Test the flash (power on self-test) More...

void	ext_flash_init (void)
	Initialise the external flash. More...

Detailed Description

Function Documentation

void ext_flash_close ( void )

Close the storage driver.

This call will put the device in its lower power mode (power down).

Definition at line 288 of file ext-flash.c.

References board_spi_close(), and power_down().

Referenced by ext_flash_init(), and ext_flash_test().

bool ext_flash_erase	(	size_t	offset,
		size_t	length
	)

Erase storage sectors corresponding to the range.

Parameters

offset	Address to start erasing
length	Number of bytes to erase

Returns: True when successful.

The erase operation will be sector-wise, therefore a call to this function will generally start the erase procedure at an address lower than offset

Definition at line 389 of file ext-flash.c.

References BLS_CODE_SECTOR_ERASE, board_spi_write(), deselect(), select_on_bus(), wait_ready(), and write_enable().

void ext_flash_init ( void )

Initialise the external flash.

This function will explicitly put the part in its lowest power mode (power-down).

In order to perform any operation, the caller must first wake the device up by calling ext_flash_open()

Definition at line 449 of file ext-flash.c.

References ext_flash_close(), and ext_flash_open().

Referenced by board_init().

bool ext_flash_open ( void )

Initialize storage driver.

Returns: True when successful.

Definition at line 271 of file ext-flash.c.

References board_spi_open(), deselect(), power_standby(), and verify_part().

Referenced by ext_flash_init(), and ext_flash_test().

bool ext_flash_read	(	size_t	offset,
		size_t	length,
		uint8_t *	buf
	)

Read storage content.

Parameters

offset	Address to read from
length	Number of bytes to read
buf	Buffer where to store the read bytes

Returns: True when successful.

buf must be allocated by the caller

Definition at line 297 of file ext-flash.c.

References BLS_CODE_READ, board_spi_read(), board_spi_write(), deselect(), select_on_bus(), and wait_ready().

bool ext_flash_test ( void )

Test the flash (power on self-test)

Returns: True when successful.

Definition at line 438 of file ext-flash.c.

References ext_flash_close(), and ext_flash_open().

bool ext_flash_write	(	size_t	offset,
		size_t	length,
		const uint8_t *	buf
	)

Write to storage sectors.

Parameters

offset	Address to write to
length	Number of bytes to write
buf	Buffer holding the bytes to be written

Returns: True when successful.

Definition at line 332 of file ext-flash.c.

References BLS_CODE_PROGRAM, board_spi_write(), deselect(), select_on_bus(), wait_ready(), and write_enable().

static void power_down ( void )

static

Put the device in power save mode.

No access to data; only the status register is accessible.

Definition at line 198 of file ext-flash.c.

References BLS_CODE_PD, board_spi_write(), deselect(), select_on_bus(), verify_part(), and wait_ready().

Referenced by ext_flash_close().

static bool power_standby ( void )

static

Take device out of power save mode and prepare it for normal operation.

Returns: True if the command was written successfully

Definition at line 232 of file ext-flash.c.

References BLS_CODE_RPD, board_spi_write(), deselect(), select_on_bus(), and wait_ready().

Referenced by ext_flash_open().

static uint8_t verify_part ( void )

static

Verify the flash part.

Return values

VERIFY_PART_OK	The part was identified successfully
VERIFY_PART_ERROR	There was an error communicating with the part
VERIFY_PART_POWERED_DOWN	Communication was successful, but the part was powered down

Definition at line 162 of file ext-flash.c.

References BLS_CODE_MDID, board_spi_read(), board_spi_write(), deselect(), and select_on_bus().

Referenced by ext_flash_open(), and power_down().

static bool wait_ready ( void )

static

Wait till previous erase/program operation completes.