A SPI Master, used for communicating with SPI slave devices. More...

#include <SPI.h>

Public Member Functions
	SPI (PinName mosi, PinName miso, PinName sclk, PinName _unused=NC)
	Create a SPI master connected to the specified pins.
void	format (int bits, int mode=0)
	Configure the data transmission format.
void	frequency (int hz=1000000)
	Set the spi bus clock frequency.
virtual int	write (int value)
	Write to the SPI Slave and return the response.
virtual int	transfer (uint8_t tx_buffer, int tx_length, uint8_t rx_buffer, int rx_length, const event_callback_t &callback, int event=SPI_EVENT_COMPLETE)
	Start non-blocking SPI transfer using 8bit buffers.
virtual int	transfer (uint16_t tx_buffer, int tx_length, uint16_t rx_buffer, int rx_length, const event_callback_t &callback, int event=SPI_EVENT_COMPLETE)
	Start non-blocking SPI transfer using 16bit buffers.
virtual int	transfer (uint32_t tx_buffer, int tx_length, uint32_t rx_buffer, int rx_length, const event_callback_t &callback, int event=SPI_EVENT_COMPLETE)
	Start non-blocking SPI transfer using 32bit buffers.
void	abort_transfer ()
	Abort the on-going SPI transfer, and continue with transfer's in the queue if any.
void	clear_transfer_buffer ()
	Clear the transaction buffer.
void	abort_all_transfers ()
	Clear the transaction buffer and abort on-going transfer.
int	set_dma_usage (DMAUsage usage)
	Configure DMA usage suggestion for non-blocking transfers.
Protected Member Functions
void	irq_handler_asynch (void)
	SPI IRQ handler.
int	transfer (void tx_buffer, int tx_length, void rx_buffer, int rx_length, unsigned char bit_width, const event_callback_t &callback, int event)
	Common transfer method.
int	queue_transfer (void tx_buffer, int tx_length, void rx_buffer, int rx_length, unsigned char bit_width, const event_callback_t &callback, int event)
void	start_transfer (void tx_buffer, int tx_length, void rx_buffer, int rx_length, unsigned char bit_width, const event_callback_t &callback, int event)
	Configures a callback, spi peripheral and initiate a new transfer.
void	start_transaction (transaction_t *data)
	Start a new transaction.
void	dequeue_transaction ()
	Dequeue a transaction.

Detailed Description

A SPI Master, used for communicating with SPI slave devices.

The default format is set to 8-bits, mode 0, and a clock frequency of 1MHz

Most SPI devices will also require Chip Select and Reset signals. These can be controlled using <DigitalOut> pins

Example:

 // Send a byte to a SPI slave, and record the response

 #include "mbed.h"

 SPI device(p5, p6, p7); // mosi, miso, sclk

 int main() {
     int response = device.write(0xFF);
 }

Definition at line 55 of file SPI.h.

Constructor & Destructor Documentation

SPI	(	PinName	mosi,
		PinName	miso,
		PinName	sclk,
		PinName	_unused = `NC`
	)

Create a SPI master connected to the specified pins.

Pin Options: (5, 6, 7) or (11, 12, 13)

mosi or miso can be specfied as NC if not used

Parameters:

mosi	SPI Master Out, Slave In pin
miso	SPI Master In, Slave Out pin
sclk	SPI Clock pin

Definition at line 26 of file SPI.cpp.

Member Function Documentation

void abort_all_transfers ( )

Clear the transaction buffer and abort on-going transfer.

Definition at line 96 of file SPI.cpp.

void abort_transfer ( void )

Abort the on-going SPI transfer, and continue with transfer's in the queue if any.

Definition at line 80 of file SPI.cpp.

void clear_transfer_buffer ( )

Clear the transaction buffer.

Definition at line 89 of file SPI.cpp.

void dequeue_transaction ( ) [protected]

Dequeue a transaction.

Definition at line 150 of file SPI.cpp.

void format	(	int	bits,
		int	mode = `0`
	)

Configure the data transmission format.

Parameters:

bits	Number of bits per SPI frame (4 - 16)
mode	Clock polarity and phase mode (0 - 3)

 mode | POL PHA
 -----+--------
   0  |  0   0
   1  |  0   1
   2  |  1   0
   3  |  1   1

Definition at line 40 of file SPI.cpp.

void frequency ( int hz = 1000000 )

Set the spi bus clock frequency.

Parameters:

hz	SCLK frequency in hz (default = 1MHz)

Definition at line 47 of file SPI.cpp.

void irq_handler_asynch ( void ) [protected]

SPI IRQ handler.

Definition at line 162 of file SPI.cpp.

int queue_transfer	(	void *	tx_buffer,
		int	tx_length,
		void *	rx_buffer,
		int	rx_length,
		unsigned char	bit_width,
		const event_callback_t &	callback,
		int	event
	)		`[protected]`

Parameters:

tx_buffer	The TX buffer with data to be transfered. If NULL is passed, the default SPI value is sent
tx_length	The length of TX buffer
rx_buffer	The RX buffer which is used for received data. If NULL is passed, received data are ignored
rx_length	The length of RX buffer
bit_width	The buffers element width
callback	The event callback function
event	The logical OR of events to modify

Returns:: Zero if a transfer was added to the queue, or -1 if the queue is full

Definition at line 111 of file SPI.cpp.

int set_dma_usage ( DMAUsage usage )

Configure DMA usage suggestion for non-blocking transfers.

Parameters:

usage The usage DMA hint for peripheral

Returns:: Zero if the usage was set, -1 if a transaction is on-going

Definition at line 102 of file SPI.cpp.

void start_transaction ( transaction_t * data ) [protected]

Start a new transaction.

Parameters:

data	Transaction data

Definition at line 145 of file SPI.cpp.

void start_transfer	(	void *	tx_buffer,
		int	tx_length,
		void *	rx_buffer,
		int	rx_length,
		unsigned char	bit_width,
		const event_callback_t &	callback,
		int	event
	)		`[protected]`

Configures a callback, spi peripheral and initiate a new transfer.

Parameters:

tx_buffer	The TX buffer with data to be transfered. If NULL is passed, the default SPI value is sent
tx_length	The length of TX buffer
rx_buffer	The RX buffer which is used for received data. If NULL is passed, received data are ignored
rx_length	The length of RX buffer
bit_width	The buffers element width
callback	The event callback function
event	The logical OR of events to modify

Definition at line 135 of file SPI.cpp.

int transfer	(	void *	tx_buffer,
		int	tx_length,
		void *	rx_buffer,
		int	rx_length,
		unsigned char	bit_width,
		const event_callback_t &	callback,
		int	event
	)		`[protected]`

Common transfer method.

Parameters:

tx_buffer	The TX buffer with data to be transfered. If NULL is passed, the default SPI value is sent
tx_length	The length of TX buffer
rx_buffer	The RX buffer which is used for received data. If NULL is passed, received data are ignored
rx_length	The length of RX buffer
bit_width	The buffers element width
callback	The event callback function
event	The logical OR of events to modify

Returns:: Zero if the transfer has started or was added to the queue, or -1 if SPI peripheral is busy/buffer is full

Definition at line 71 of file SPI.cpp.

virtual int transfer	(	uint16_t *	tx_buffer,
		int	tx_length,
		uint16_t *	rx_buffer,
		int	rx_length,
		const event_callback_t &	callback,
		int	event = `SPI_EVENT_COMPLETE`
	)		`[virtual]`

Start non-blocking SPI transfer using 16bit buffers.

Parameters:

tx_buffer	The TX buffer with data to be transfered. If NULL is passed, the default SPI value is sent
tx_length	The length of TX buffer
rx_buffer	The RX buffer which is used for received data. If NULL is passed, received data are ignored
rx_length	The length of RX buffer
callback	The event callback function
event	The logical OR of events to modify

Returns:: Zero if the transfer has started, or -1 if SPI peripheral is busy

Definition at line 133 of file SPI.h.

virtual int transfer	(	uint32_t *	tx_buffer,
		int	tx_length,
		uint32_t *	rx_buffer,
		int	rx_length,
		const event_callback_t &	callback,
		int	event = `SPI_EVENT_COMPLETE`
	)		`[virtual]`

Start non-blocking SPI transfer using 32bit buffers.

Parameters:

tx_buffer	The TX buffer with data to be transfered. If NULL is passed, the default SPI value is sent
tx_length	The length of TX buffer
rx_buffer	The RX buffer which is used for received data. If NULL is passed, received data are ignored
rx_length	The length of RX buffer
callback	The event callback function
event	The logical OR of events to modify

Returns:: Zero if the transfer has started, or -1 if SPI peripheral is busy

Definition at line 149 of file SPI.h.

virtual int transfer	(	uint8_t *	tx_buffer,
		int	tx_length,
		uint8_t *	rx_buffer,
		int	rx_length,
		const event_callback_t &	callback,
		int	event = `SPI_EVENT_COMPLETE`
	)		`[virtual]`

Start non-blocking SPI transfer using 8bit buffers.

Parameters:

tx_buffer	The TX buffer with data to be transfered. If NULL is passed, the default SPI value is sent
tx_length	The length of TX buffer
rx_buffer	The RX buffer which is used for received data. If NULL is passed, received data are ignored
rx_length	The length of RX buffer
callback	The event callback function
event	The logical OR of events to modify

Returns:: Zero if the transfer has started, or -1 if SPI peripheral is busy

Definition at line 117 of file SPI.h.

int write ( int value ) [virtual]

Write to the SPI Slave and return the response.

Parameters:

value Data to be sent to the SPI slave

Returns:: Response from the SPI slave

Definition at line 64 of file SPI.cpp.

Type:	Library
Created:	26 May 2015
Imports:	8
Forks:	0
Commits:	551
Dependents:	0
Dependencies:	0
Followers:	0

SPI Class Reference

Public Member Functions

Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

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SPI Class Reference

Public Member Functions

Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Repository toolbox

Repository details

Important Information for this Arm website

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