* application.
*
* \code
- * // Initialise the SPI driver before first use
+ * // Initialize the SPI driver before first use
* SPI_Init(SPI_SPEED_FCPU_DIV_2 | SPI_ORDER_MSB_FIRST | SPI_SCK_LEAD_FALLING |
* SPI_SAMPLE_TRAILING | SPI_MODE_MASTER);
*
/** SPI data order mask for \c SPI_Init(). Indicates that data should be shifted out MSB first. */
#define SPI_ORDER_MSB_FIRST (0 << DORD)
- /** SPI data order mask for \c SPI_Init(). Indicates that data should be shifted out MSB first. */
+ /** SPI data order mask for \c SPI_Init(). Indicates that data should be shifted out LSB first. */
#define SPI_ORDER_LSB_FIRST (1 << DORD)
//@}
//@}
/* Inline Functions: */
- /** Initialises the SPI subsystem, ready for transfers. Must be called before calling any other
+ /** Initializes the SPI subsystem, ready for transfers. Must be called before calling any other
* SPI routines.
*
* \param[in] SPIOptions SPI Options, a mask consisting of one of each of the \c SPI_SPEED_*,
*/
static inline void SPI_Init(const uint8_t SPIOptions)
{
- DDRB |= ((1 << 1) | (1 << 2));
- DDRB &= ~((1 << 0) | (1 << 3));
- PORTB |= ((1 << 0) | (1 << 3));
+ /* Prevent high rise times on PB.0 (/SS) from forcing a change to SPI slave mode */
+ DDRB |= (1 << 0);
+ PORTB |= (1 << 0);
- SPCR = ((1 << SPE) | SPIOptions);
+ DDRB |= ((1 << 1) | (1 << 2));
+ DDRB &= ~(1 << 3);
+ PORTB |= (1 << 3);
if (SPIOptions & SPI_USE_DOUBLESPEED)
SPSR |= (1 << SPI2X);
else
SPSR &= ~(1 << SPI2X);
+
+ /* Switch /SS to input mode after configuration to allow for forced mode changes */
+ DDRB &= ~(1 << 0);
+
+ SPCR = ((1 << SPE) | SPIOptions);
}
/** Turns off the SPI driver, disabling and returning used hardware to their default configuration. */
SPCR = 0;
SPSR = 0;
}
+
+ /** Retrieves the currently selected SPI mode, once the SPI interface has been configured.
+ *
+ * \return \ref SPI_MODE_MASTER if the interface is currently in SPI Master mode, \ref SPI_MODE_SLAVE otherwise
+ */
+ static inline uint8_t SPI_GetCurrentMode(void) ATTR_ALWAYS_INLINE;
+ static inline uint8_t SPI_GetCurrentMode(void)
+ {
+ return (SPCR & SPI_MODE_MASTER);
+ }
/** Sends and receives a byte through the SPI interface, blocking until the transfer is complete.
*