Kenji Arai / mbed-os_TYBLE16

Dependents:   TYBLE16_simple_data_logger TYBLE16_MP3_Air

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SPI Class Reference

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

#include <SPI.h>

Inherits NonCopyable< SPI >.

Inherited by UnlockedSPI, and UnlockedSPI.

Public Member Functions

 SPI (PinName mosi, PinName miso, PinName sclk, PinName ssel=NC)
 Create a SPI master connected to the specified pins.
 SPI (PinName mosi, PinName miso, PinName sclk, PinName ssel, use_gpio_ssel_t)
 Create a SPI master connected to the specified pins.
 SPI (const spi_pinmap_t &static_pinmap)
 Create a SPI master connected to the specified pins.
 SPI (const spi_pinmap_t &static_pinmap, PinName ssel)
 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 write (const char *tx_buffer, int tx_length, char *rx_buffer, int rx_length)
 Write to the SPI Slave and obtain the response.
virtual void lock (void)
 Acquire exclusive access to this SPI bus.
virtual void unlock (void)
 Release exclusive access to this SPI bus.
void select (void)
 Assert the Slave Select line, acquiring exclusive access to this SPI bus.
void deselect (void)
 Deassert the Slave Select line, releasing exclusive access to this SPI bus.
void set_default_write_value (char data)
 Set default write data.
template<typename Type >
int transfer (const Type *tx_buffer, int tx_length, Type *rx_buffer, int rx_length, const event_callback_t &callback, int event=SPI_EVENT_COMPLETE)
 Start non-blocking SPI transfer using 8bit buffers.
void abort_transfer ()
 Abort the on-going SPI transfer, and continue with transfers in the queue, if any.
void clear_transfer_buffer ()
 Clear the queue of transfers.
void abort_all_transfers ()
 Clear the queue of transfers and abort the 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 interrupt handler.
int transfer (const void *tx_buffer, int tx_length, void *rx_buffer, int rx_length, unsigned char bit_width, const event_callback_t &callback, int event)
 Start the transfer or put it on the queue.
int queue_transfer (const void *tx_buffer, int tx_length, void *rx_buffer, int rx_length, unsigned char bit_width, const event_callback_t &callback, int event)
 Put a transfer on the transfer queue.
void start_transfer (const void *tx_buffer, int tx_length, void *rx_buffer, int rx_length, unsigned char bit_width, const event_callback_t &callback, int event)
 Configure a callback, SPI peripheral, and initiate a new transfer.

Private Member Functions

 MBED_DEPRECATED ("Invalid copy construction of a NonCopyable resource.") NonCopyable(const NonCopyable &)
 NonCopyable copy constructor.
 MBED_DEPRECATED ("Invalid copy assignment of a NonCopyable resource.") NonCopyable &operator
 NonCopyable copy assignment operator.

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.

Note:
Synchronization level: Thread safe

Example of how to send a byte to a SPI slave and record the response:

 #include "mbed.h"

 SPI device(SPI_MOSI, SPI_MISO, SPI_SCLK)

 DigitalOut chip_select(SPI_CS);

 int main() {
     device.lock();
     chip_select = 0;

     int response = device.write(0xFF);

     chip_select = 1;
     device.unlock();
 }

Example using hardware Chip Select line:

 #include "mbed.h"

 SPI device(SPI_MOSI, SPI_MISO, SPI_SCLK, SPI_CS)

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

Definition at line 98 of file SPI.h.


Constructor & Destructor Documentation

SPI ( PinName  mosi,
PinName  miso,
PinName  sclk,
PinName  ssel = NC 
)

Create a SPI master connected to the specified pins.

Note:
This constructor passes the SSEL pin selection to the target HAL. Not all targets support SSEL, so this cannot be relied on in portable code. Portable code should use the alternative constructor that uses GPIO for SSEL.
You can specify mosi or miso as NC if not used.
Parameters:
mosiSPI Master Out, Slave In pin.
misoSPI Master In, Slave Out pin.
sclkSPI Clock pin.
sselSPI Chip Select pin.

Definition at line 31 of file SPI.cpp.

SPI ( PinName  mosi,
PinName  miso,
PinName  sclk,
PinName  ssel,
use_gpio_ssel_t   
)

Create a SPI master connected to the specified pins.

Note:
This constructor manipulates the SSEL pin as a GPIO output using a DigitalOut object. This should work on any target, and permits the use of select() and deselect() methods to keep the pin asserted between transfers.
You can specify mosi or miso as NC if not used.
Parameters:
mosiSPI Master Out, Slave In pin.
misoSPI Master In, Slave Out pin.
sclkSPI Clock pin.
sselSPI Chip Select pin.

Definition at line 53 of file SPI.cpp.

SPI ( const spi_pinmap_t &  static_pinmap )

Create a SPI master connected to the specified pins.

Note:
This constructor passes the SSEL pin selection to the target HAL. Not all targets support SSEL, so this cannot be relied on in portable code. Portable code should use the alternative constructor that uses GPIO for SSEL.
You can specify mosi or miso as NC if not used.
Parameters:
static_pinmapreference to structure which holds static pinmap.

Definition at line 74 of file SPI.cpp.

SPI ( const spi_pinmap_t &  static_pinmap,
PinName  ssel 
)

Create a SPI master connected to the specified pins.

Note:
This constructor manipulates the SSEL pin as a GPIO output using a DigitalOut object. This should work on any target, and permits the use of select() and deselect() methods to keep the pin asserted between transfers.
You can specify mosi or miso as NC if not used.
Parameters:
static_pinmapreference to structure which holds static pinmap.
sselSPI Chip Select pin.

Definition at line 91 of file SPI.cpp.


Member Function Documentation

void abort_all_transfers (  )

Clear the queue of transfers and abort the on-going transfer.

Definition at line 306 of file SPI.cpp.

void abort_transfer ( void   )

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

Definition at line 290 of file SPI.cpp.

void clear_transfer_buffer (  )

Clear the queue of transfers.

Definition at line 299 of file SPI.cpp.

void deselect ( void   )

Deassert the Slave Select line, releasing exclusive access to this SPI bus.

Definition at line 263 of file SPI.cpp.

void format ( int  bits,
int  mode = 0 
)

Configure the data transmission format.

Parameters:
bitsNumber of bits per SPI frame (4 - 16).
modeClock polarity and phase mode (0 - 3).
 mode | POL PHA
 -----+--------
   0  |  0   0
   1  |  0   1
   2  |  1   0
   3  |  1   1

Definition at line 179 of file SPI.cpp.

void frequency ( int  hz = 1000000 )

Set the SPI bus clock frequency.

Parameters:
hzClock frequency in Hz (default = 1MHz).

Definition at line 195 of file SPI.cpp.

void irq_handler_asynch ( void   ) [protected]

SPI interrupt handler.

Definition at line 395 of file SPI.cpp.

void lock ( void   ) [virtual]

Acquire exclusive access to this SPI bus.

Definition at line 244 of file SPI.cpp.

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

Put a transfer on the transfer queue.

Parameters:
tx_bufferThe TX buffer with data to be transferred. If NULL is passed, the default SPI value is sent.
tx_lengthThe length of TX buffer in bytes.
rx_bufferThe RX buffer which is used for received data. If NULL is passed, received data are ignored.
rx_lengthThe length of RX buffer in bytes.
bit_widthThe buffers element width in bits.
callbackThe event callback function.
eventThe event mask of events to modify.
Returns:
Operation success.
Return values:
0A transfer was added to the queue.
-1Transfer can't be added because queue is full.

Definition at line 321 of file SPI.cpp.

void select ( void   )

Assert the Slave Select line, acquiring exclusive access to this SPI bus.

If use_gpio_ssel was not passed to the constructor, this only acquires exclusive access; it cannot assert the Slave Select line.

Definition at line 249 of file SPI.cpp.

void set_default_write_value ( char  data )

Set default write data.

SPI requires the master to send some data during a read operation. Different devices may require different default byte values. For example: A SD Card requires default bytes to be 0xFF.

Parameters:
dataDefault character to be transmitted during a read operation.

Definition at line 271 of file SPI.cpp.

int set_dma_usage ( DMAUsage  usage )

Configure DMA usage suggestion for non-blocking transfers.

Parameters:
usageThe usage DMA hint for peripheral.
Returns:
Result of the operation.
Return values:
0The usage was set.
-1Usage cannot be set as there is an ongoing transaction.

Definition at line 312 of file SPI.cpp.

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

Configure a callback, SPI peripheral, and initiate a new transfer.

Parameters:
tx_bufferThe TX buffer with data to be transferred. If NULL is passed, the default SPI value is sent.
tx_lengthThe length of TX buffer in bytes.
rx_bufferThe RX buffer which is used for received data. If NULL is passed, received data are ignored.
rx_lengthThe length of RX buffer in bytes.
bit_widthThe buffers element width.
callbackThe event callback function.
eventThe event mask of events to modify.

Definition at line 350 of file SPI.cpp.

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

Start the transfer or put it on the queue.

Parameters:
tx_bufferThe TX buffer with data to be transferred. If NULL is passed, the default SPI value is sent
tx_lengthThe length of TX buffer in bytes.
rx_bufferThe RX buffer which is used for received data. If NULL is passed, received data are ignored.
rx_lengthThe length of RX buffer in bytes.
bit_widthThe buffers element width in bits.
callbackThe event callback function.
eventThe event mask of events to modify.
Returns:
Operation success.
Return values:
0A transfer was started or added to the queue.
-1Transfer can't be added because queue is full.

Definition at line 281 of file SPI.cpp.

int transfer ( const Type *  tx_buffer,
int  tx_length,
Type *  rx_buffer,
int  rx_length,
const event_callback_t &  callback,
int  event = SPI_EVENT_COMPLETE 
)

Start non-blocking SPI transfer using 8bit buffers.

This function locks the deep sleep until any event has occurred.

Parameters:
tx_bufferThe TX buffer with data to be transferred. If NULL is passed, the default SPI value is sent.
tx_lengthThe length of TX buffer in bytes.
rx_bufferThe RX buffer which is used for received data. If NULL is passed, received data are ignored.
rx_lengthThe length of RX buffer in bytes.
callbackThe event callback function.
eventThe event mask of events to modify.
See also:
spi_api.h for SPI events.
Returns:
Operation result.
Return values:
0If the transfer has started.
-1If SPI peripheral is busy.

Definition at line 259 of file SPI.h.

void unlock ( void   ) [virtual]

Release exclusive access to this SPI bus.

Definition at line 258 of file SPI.cpp.

int write ( int  value ) [virtual]

Write to the SPI Slave and return the response.

Parameters:
valueData to be sent to the SPI slave.
Returns:
Response from the SPI slave.

Definition at line 221 of file SPI.cpp.

int write ( const char *  tx_buffer,
int  tx_length,
char *  rx_buffer,
int  rx_length 
) [virtual]

Write to the SPI Slave and obtain the response.

The total number of bytes sent and received will be the maximum of tx_length and rx_length. The bytes written will be padded with the value 0xff.

Parameters:
tx_bufferPointer to the byte-array of data to write to the device.
tx_lengthNumber of bytes to write, may be zero.
rx_bufferPointer to the byte-array of data to read from the device.
rx_lengthNumber of bytes to read, may be zero.
Returns:
The number of bytes written and read from the device. This is maximum of tx_length and rx_length.

Definition at line 229 of file SPI.cpp.