LUFA Library  120219
SPI Peripheral Driver (XMEGA)

Functions

static void SPI_Init (SPI_t *const SPI, const uint8_t SPIOptions)
static void SPI_Disable (SPI_t *const SPI)
static uint8_t SPI_GetCurrentMode (SPI_t *const SPI) ATTR_ALWAYS_INLINE
static uint8_t SPI_TransferByte (SPI_t *const SPI, const uint8_t Byte) ATTR_ALWAYS_INLINE
static void SPI_SendByte (SPI_t *const SPI, const uint8_t Byte) ATTR_ALWAYS_INLINE
static uint8_t SPI_ReceiveByte (SPI_t *const SPI) ATTR_ALWAYS_INLINE ATTR_WARN_UNUSED_RESULT

SPI Prescaler Configuration Masks

#define SPI_SPEED_FCPU_DIV_2   SPI_USE_DOUBLESPEED
#define SPI_SPEED_FCPU_DIV_4   0
#define SPI_SPEED_FCPU_DIV_8   (SPI_USE_DOUBLESPEED | (1 << SPI_PRESCALER_gp))
#define SPI_SPEED_FCPU_DIV_16   (1 << SPI_PRESCALER_gp)
#define SPI_SPEED_FCPU_DIV_32   (SPI_USE_DOUBLESPEED | (2 << SPI_PRESCALER_gp))
#define SPI_SPEED_FCPU_DIV_64   (2 << SPI_PRESCALER_gp)
#define SPI_SPEED_FCPU_DIV_128   (3 << SPI_PRESCALER_gp)

SPI SCK Polarity Configuration Masks

#define SPI_SCK_LEAD_RISING   0
#define SPI_SCK_LEAD_FALLING   SPI_MODE1_bm

SPI Sample Edge Configuration Masks

#define SPI_SAMPLE_LEADING   0
#define SPI_SAMPLE_TRAILING   SPI_MODE0_bm

SPI Data Ordering Configuration Masks

#define SPI_ORDER_MSB_FIRST   0
#define SPI_ORDER_LSB_FIRST   SPI_DORD_bm

SPI Mode Configuration Masks

#define SPI_MODE_SLAVE   0
#define SPI_MODE_MASTER   SPI_MASTER_bm

Detailed Description

Module Description

Driver for the hardware SPI port(s) available on XMEGA AVR microcontroller models. This module provides an easy to use driver for the setup and transfer of data over the AVR's SPI ports.

Note:
This file should not be included directly. It is automatically included as needed by the SPI driver dispatch header located in LUFA/Drivers/Peripheral/SPI.h.
      // Initialize the SPI driver before first use
      SPI_Init(&SPIC,
               SPI_SPEED_FCPU_DIV_2 | SPI_ORDER_MSB_FIRST | SPI_SCK_LEAD_FALLING |
               SPI_SAMPLE_TRAILING | SPI_MODE_MASTER);

      // Send several bytes, ignoring the returned data
      SPI_SendByte(&SPIC, 0x01);
      SPI_SendByte(&SPIC, 0x02);
      SPI_SendByte(&SPIC, 0x03);

      // Receive several bytes, sending a dummy 0x00 byte each time
      uint8_t Byte1 = SPI_ReceiveByte(&SPIC);
      uint8_t Byte2 = SPI_ReceiveByte(&SPIC);
      uint8_t Byte3 = SPI_ReceiveByte(&SPIC);

      // Send a byte, and store the received byte from the same transaction
      uint8_t ResponseByte = SPI_TransferByte(&SPIC, 0xDC);

Define Documentation

#define SPI_MODE_MASTER   SPI_MASTER_bm

SPI mode mask for SPI_Init(). Indicates that the SPI interface should be initialized into master mode.

#define SPI_MODE_SLAVE   0

SPI mode mask for SPI_Init(). Indicates that the SPI interface should be initialized into slave mode.

#define SPI_ORDER_LSB_FIRST   SPI_DORD_bm

SPI data order mask for SPI_Init(). Indicates that data should be shifted out LSB first.

#define SPI_ORDER_MSB_FIRST   0

SPI data order mask for SPI_Init(). Indicates that data should be shifted out MSB first.

#define SPI_SAMPLE_LEADING   0

SPI data sample mode mask for SPI_Init(). Indicates that the data should sampled on the leading edge.

#define SPI_SAMPLE_TRAILING   SPI_MODE0_bm

SPI data sample mode mask for SPI_Init(). Indicates that the data should be sampled on the trailing edge.

#define SPI_SCK_LEAD_FALLING   SPI_MODE1_bm

SPI clock polarity mask for SPI_Init(). Indicates that the SCK should lead on the falling edge.

#define SPI_SCK_LEAD_RISING   0

SPI clock polarity mask for SPI_Init(). Indicates that the SCK should lead on the rising edge.

#define SPI_SPEED_FCPU_DIV_128   (3 << SPI_PRESCALER_gp)

SPI prescaler mask for SPI_Init(). Divides the system clock by a factor of 128.

#define SPI_SPEED_FCPU_DIV_16   (1 << SPI_PRESCALER_gp)

SPI prescaler mask for SPI_Init(). Divides the system clock by a factor of 16.

#define SPI_SPEED_FCPU_DIV_2   SPI_USE_DOUBLESPEED

SPI prescaler mask for SPI_Init(). Divides the system clock by a factor of 2.

#define SPI_SPEED_FCPU_DIV_32   (SPI_USE_DOUBLESPEED | (2 << SPI_PRESCALER_gp))

SPI prescaler mask for SPI_Init(). Divides the system clock by a factor of 32.

#define SPI_SPEED_FCPU_DIV_4   0

SPI prescaler mask for SPI_Init(). Divides the system clock by a factor of 4.

#define SPI_SPEED_FCPU_DIV_64   (2 << SPI_PRESCALER_gp)

SPI prescaler mask for SPI_Init(). Divides the system clock by a factor of 64.

#define SPI_SPEED_FCPU_DIV_8   (SPI_USE_DOUBLESPEED | (1 << SPI_PRESCALER_gp))

SPI prescaler mask for SPI_Init(). Divides the system clock by a factor of 8.


Function Documentation

static void SPI_Disable ( SPI_t *const  SPI) [inline, static]

Turns off the SPI driver, disabling and returning used hardware to their default configuration.

Parameters:
[in,out]SPIPointer to the base of the SPI peripheral within the device.
static uint8_t SPI_GetCurrentMode ( SPI_t *const  SPI) [inline, static]

Retrieves the currently selected SPI mode, once the SPI interface has been configured.

Parameters:
[in,out]SPIPointer to the base of the SPI peripheral within the device.
Returns:
SPI_MODE_MASTER if the interface is currently in SPI Master mode, SPI_MODE_SLAVE otherwise
static void SPI_Init ( SPI_t *const  SPI,
const uint8_t  SPIOptions 
) [inline, static]

Initializes the SPI subsystem, ready for transfers. Must be called before calling any other SPI routines.

Parameters:
[in,out]SPIPointer to the base of the SPI peripheral within the device.
[in]SPIOptionsSPI Options, a mask consisting of one of each of the SPI_SPEED_*, SPI_SCK_*, SPI_SAMPLE_*, SPI_ORDER_* and SPI_MODE_* masks.
static uint8_t SPI_ReceiveByte ( SPI_t *const  SPI) [inline, static]

Sends a dummy byte through the SPI interface, blocking until the transfer is complete. The response byte from the attached SPI device is returned.

Parameters:
[in,out]SPIPointer to the base of the SPI peripheral within the device.
Returns:
The response byte from the attached SPI device.
static void SPI_SendByte ( SPI_t *const  SPI,
const uint8_t  Byte 
) [inline, static]

Sends a byte through the SPI interface, blocking until the transfer is complete. The response byte sent to from the attached SPI device is ignored.

Parameters:
[in,out]SPIPointer to the base of the SPI peripheral within the device.
[in]ByteByte to send through the SPI interface.
static uint8_t SPI_TransferByte ( SPI_t *const  SPI,
const uint8_t  Byte 
) [inline, static]

Sends and receives a byte through the SPI interface, blocking until the transfer is complete.

Parameters:
[in,out]SPIPointer to the base of the SPI peripheral within the device.
[in]ByteByte to send through the SPI interface.
Returns:
Response byte from the attached SPI device.
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