Description

Driver that communicates with an On Semiconductor CAT25M EEPROM using SPI.

File(s):

Reference:

On Semiconductor CAT25M01 1 Mbit SPI Serial CMOS EEPROM datasheet

Macros
#define	PX_CAT25M_EEPROM_SIZE_BYTES (PX_CAT25M_PAGES * PX_CAT25M_PAGE_SIZE)
	EEPROM size (in bytes) More...

#define	PX_CAT25M_ADR_MAX (PX_CAT25M_EEPROM_SIZE_BYTES - 1)
	Maximum adress. More...

#define	PX_CAT25M_MAX_SPI_CLOCK_HZ 10000000
	Maximum SPI Clock rate. More...

#define	PX_CAT25M_SPI_MODE PX_SPI_MODE0
	SPI Clock / Data phase. More...

#define	PX_CAT25M_SPI_DATA_ORDER PX_SPI_DATA_ORDER_MSB
	SPI Data order. More...

#define	PX_CAT25M_CFG_DEVICE PX_CAT25M01
	Specify device. More...

Typedefs
typedef uint32_t	px_cat25m_adr_t
	Address size. More...

Functions
void	px_cat25m_init (px_spi_handle_t *handle)
	Initialise driver. More...

void	px_cat25m_rd (void *buf, px_cat25m_adr_t adr, size_t nr_of_bytes)
	Read data from EEPROM. More...

void	px_cat25m_rd_page (void *buf, uint16_t page)
	Read a page from EEPROM. More...

void	px_cat25m_rd_page_offset (void *buf, uint16_t page, uint8_t start_byte_in_page, size_t nr_of_bytes)
	Partial read of data in a page of EEPROM. More...

void	px_cat25m_wr_page (const void *buf, uint16_t page)
	Write a page from EEPROM. More...

void	px_cat25m_wr_page_offset (const void *buf, uint16_t page, uint8_t start_byte_in_page, size_t nr_of_bytes)
	Partial write of data in a page of EEPROM. More...

bool	px_cat25m_ready (void)
	Check if EEPROM is ready for the next read or write access. More...

uint8_t	px_cat25m_status_rd (void)
	Read the status register of the EEPROM. More...

void	px_cat25m_status_wr (uint8_t status)
	Write to the status register of the EEPROM. More...

void	px_cat25m_wr_en (void)
	Enable writing. More...

void	px_cat25m_wr_dis (void)
	Disable writing. More...

List CAT25M devices
#define	PX_CAT25M01 0

#define	PX_CAT25M02 1

Status register
#define	PX_CAT25M_STATUS_WPEN 7
	Write Protect Enable. More...

#define	PX_CAT25M_STATUS_IPL 6
	Identification Page Latch. More...

#define	PX_CAT25M_STATUS_LIP 4
	Lock Identification Page. More...

#define	PX_CAT25M_STATUS_BP1 3
	Block Protect bit 1. More...

#define	PX_CAT25M_STATUS_BP0 2
	Block Protect bit 0. More...

#define	PX_CAT25M_STATUS_WEL 1
	Write Enable Latch. More...

#define	PX_CAT25M_STATUS_RDY 0
	Ready (inverted) More...

Macro Definition Documentation

◆ PX_CAT25M_EEPROM_SIZE_BYTES

#define PX_CAT25M_EEPROM_SIZE_BYTES (PX_CAT25M_PAGES * PX_CAT25M_PAGE_SIZE)

EEPROM size (in bytes)

Definition at line 71 of file px_cat25m.h.

◆ PX_CAT25M_ADR_MAX

#define PX_CAT25M_ADR_MAX (PX_CAT25M_EEPROM_SIZE_BYTES - 1)

Maximum adress.

Definition at line 74 of file px_cat25m.h.

◆ PX_CAT25M_STATUS_WPEN

#define PX_CAT25M_STATUS_WPEN 7

Write Protect Enable.

Definition at line 78 of file px_cat25m.h.

◆ PX_CAT25M_STATUS_IPL

#define PX_CAT25M_STATUS_IPL 6

Identification Page Latch.

Definition at line 79 of file px_cat25m.h.

◆ PX_CAT25M_STATUS_LIP

#define PX_CAT25M_STATUS_LIP 4

Lock Identification Page.

Definition at line 80 of file px_cat25m.h.

◆ PX_CAT25M_STATUS_BP1

#define PX_CAT25M_STATUS_BP1 3

Block Protect bit 1.

Definition at line 81 of file px_cat25m.h.

◆ PX_CAT25M_STATUS_BP0

#define PX_CAT25M_STATUS_BP0 2

Block Protect bit 0.

Definition at line 82 of file px_cat25m.h.

◆ PX_CAT25M_STATUS_WEL

#define PX_CAT25M_STATUS_WEL 1

Write Enable Latch.

Definition at line 83 of file px_cat25m.h.

◆ PX_CAT25M_STATUS_RDY

#define PX_CAT25M_STATUS_RDY 0

Ready (inverted)

Definition at line 84 of file px_cat25m.h.

◆ PX_CAT25M_MAX_SPI_CLOCK_HZ

#define PX_CAT25M_MAX_SPI_CLOCK_HZ 10000000

Maximum SPI Clock rate.

Definition at line 88 of file px_cat25m.h.

◆ PX_CAT25M_SPI_MODE

#define PX_CAT25M_SPI_MODE PX_SPI_MODE0

SPI Clock / Data phase.

Definition at line 90 of file px_cat25m.h.

◆ PX_CAT25M_SPI_DATA_ORDER

#define PX_CAT25M_SPI_DATA_ORDER PX_SPI_DATA_ORDER_MSB

SPI Data order.

Definition at line 92 of file px_cat25m.h.

◆ PX_CAT25M_CFG_DEVICE

#define PX_CAT25M_CFG_DEVICE PX_CAT25M01

Specify device.

Definition at line 34 of file px_cat25m_cfg_template.h.

Typedef Documentation

◆ px_cat25m_adr_t

typedef uint32_t px_cat25m_adr_t

Address size.

Definition at line 96 of file px_cat25m.h.

Function Documentation

◆ px_cat25m_init()

void px_cat25m_init ( px_spi_handle_t * handle )

Initialise driver.

Parameters

handle SPI handle to use for SPI slave device

Definition at line 48 of file px_cat25m.c.

◆ px_cat25m_rd()

void px_cat25m_rd	(	void *	buf,
		px_cat25m_adr_t	adr,
		size_t	nr_of_bytes
	)

Read data from EEPROM.

This function reads data from EEPROM and stores it in the specified buffer.

Parameters

[out]	buf	Buffer to store read data
[in]	adr	0 to PX_CAT25M_ADR_MAX
[in]	nr_of_bytes	Number of bytes to read

Definition at line 56 of file px_cat25m.c.

◆ px_cat25m_rd_page()

void px_cat25m_rd_page	(	void *	buf,
		uint16_t	page
	)

Read a page from EEPROM.

This function reads a page of data from EEPROM and stores it in the specified buffer. The buffer must be at least PX_CAT25M_PAGE_SIZE bytes in size to accomodate a full page.

The EEPROM has PX_CAT25M_PAGES pages.

Parameters

[out]	buf	Buffer to store read data
[in]	page	0 to (PX_CAT25M_PAGES - 1)

Definition at line 78 of file px_cat25m.c.

◆ px_cat25m_rd_page_offset()

void px_cat25m_rd_page_offset	(	void *	buf,
		uint16_t	page,
		uint8_t	start_byte_in_page,
		size_t	nr_of_bytes
	)

Partial read of data in a page of EEPROM.

This function reads part of a page of data from EEPROM and stores it in the specified buffer. The buffer must be at least nr_of_bytes in size to the read data.

Note

Only read up to the end of the specified page. If the page boundary is exceeded, the index will wrap to the start of the page, i.e. only the content of the specified page will be read.

Parameters

[out]	buf	Buffer to store read data
[in]	page	0 to (PX_CAT25M_PAGES - 1)
[in]	start_byte_in_page	Index of first byte to read (0 to PX_CAT25M_PAGE_SIZE - 1)
[in]	nr_of_bytes	Number of bytes to read

Definition at line 96 of file px_cat25m.c.

◆ px_cat25m_wr_page()

void px_cat25m_wr_page	(	const void *	buf,
		uint16_t	page
	)

Write a page from EEPROM.

This function writes a page of data to EEPROM using the specified buffer as the source. The buffer must contain at least PX_CAT25M_PAGE_SIZE bytes of data.

The EEPROM has PX_CAT25M_PAGES pages.

Parameters

[in]	buf	Buffer containing data to be written
[in]	page	0 to (PX_CAT25M_PAGES - 1)

Definition at line 116 of file px_cat25m.c.

◆ px_cat25m_wr_page_offset()

void px_cat25m_wr_page_offset	(	const void *	buf,
		uint16_t	page,
		uint8_t	start_byte_in_page,
		size_t	nr_of_bytes
	)

Partial write of data in a page of EEPROM.

This function writes a part of a page of data to EEPROM using the specified buffer as source. The buffer must contain at least nr_of_bytes of data.

Note

Only write up to the end of the specified page. If the page boundary is exceeded, the index will wrap to the start of the page, i.e. only the content of the specified page will be written.

Parameters

[in]	buf	Buffer containing data to be written
[in]	page	0 to (PX_CAT25M_PAGES - 1)
[in]	start_byte_in_page	Index of first byte to write (0 to PX_CAT25M_PAGE_SIZE - 1)
[in]	nr_of_bytes	Number of bytes to write

Definition at line 138 of file px_cat25m.c.

◆ px_cat25m_ready()

bool px_cat25m_ready ( void )

Check if EEPROM is ready for the next read or write access.

When data is written to EEPROM, the microcontroller must wait until the operation is finished, before the next one is attempted. This function allows the microcontroller to do something else while waiting for the operation to finish.

Return values

true	EEPROM is ready for next read or write access.
false	EEPROM is busy writing.

Definition at line 162 of file px_cat25m.c.

◆ px_cat25m_status_rd()

uint8_t px_cat25m_status_rd ( void )

Read the status register of the EEPROM.

The status register contains flags (e.g. PX_CAT25M_STATUS_RDY). This function can be used to check that a valid and working EEPROM device is connected.

Returns: uint8_t Status register value

Definition at line 174 of file px_cat25m.c.

◆ px_cat25m_status_wr()

void px_cat25m_status_wr ( uint8_t status )

Write to the status register of the EEPROM.

Parameters

status Value to write to the status register

Definition at line 187 of file px_cat25m.c.

◆ px_cat25m_wr_en()

void px_cat25m_wr_en ( void )

Enable writing.

Definition at line 197 of file px_cat25m.c.

◆ px_cat25m_wr_dis()

void px_cat25m_wr_dis ( void )

Disable writing.

Definition at line 206 of file px_cat25m.c.

Description

Macros

Typedefs

Functions

List CAT25M devices

Status register

Macro Definition Documentation

◆ PX_CAT25M_EEPROM_SIZE_BYTES

◆ PX_CAT25M_ADR_MAX

◆ PX_CAT25M_STATUS_WPEN

◆ PX_CAT25M_STATUS_IPL

◆ PX_CAT25M_STATUS_LIP

◆ PX_CAT25M_STATUS_BP1

◆ PX_CAT25M_STATUS_BP0

◆ PX_CAT25M_STATUS_WEL

◆ PX_CAT25M_STATUS_RDY

◆ PX_CAT25M_MAX_SPI_CLOCK_HZ

◆ PX_CAT25M_SPI_MODE

◆ PX_CAT25M_SPI_DATA_ORDER

◆ PX_CAT25M_CFG_DEVICE

Typedef Documentation

◆ px_cat25m_adr_t

Function Documentation

◆ px_cat25m_init()

◆ px_cat25m_rd()

◆ px_cat25m_rd_page()

◆ px_cat25m_rd_page_offset()

◆ px_cat25m_wr_page()

◆ px_cat25m_wr_page_offset()

◆ px_cat25m_ready()

◆ px_cat25m_status_rd()

◆ px_cat25m_status_wr()

◆ px_cat25m_wr_en()

◆ px_cat25m_wr_dis()