spi Namespace Reference

Define API to define and manage SPI devices. More...

Classes
class	AbstractSPIDevice
	Contain general payload transfer API for an SPI device. More...
class	SPIDevice
	Base class for any SPI slave device. More...

Enumerations
enum class	ClockRate : uint8_t {   CLOCK_DIV_4 = 0x00 ,   CLOCK_DIV_16 = 0x01 ,   CLOCK_DIV_64 = 0x02 ,   CLOCK_DIV_128 = 0x03 ,   CLOCK_DIV_2 = 0x10 ,   CLOCK_DIV_8 = 0x11 ,   CLOCK_DIV_32 = 0x12 }
	Define SPI clock rate as a divider of MCU clock frequency. More...
enum class	DataOrder : uint8_t {   MSB_FIRST = 0 ,   LSB_FIRST = bits::BV8(DORD) }
	Bit ordering per byte. More...
enum class	Mode : uint8_t {   MODE_0 = 0 ,   MODE_1 = bits::BV8(CPHA) ,   MODE_2 = bits::BV8(CPOL) ,   MODE_3 = bits::BV8(CPHA, CPOL) }
	SPI transmission mode. More...
enum class	ChipSelect : uint8_t {   ACTIVE_LOW = 0 ,   ACTIVE_HIGH = 1 }
	Active polarity of slave selection pin. More...

Functions
void	init ()
	This function must be called once in your program, before any use of an SPI device. More...
constexpr ClockRate	compute_clockrate (uint32_t frequency)
	Calculate ClockRate for the given frequency. More...

Detailed Description

Define API to define and manage SPI devices.

SPI is available to all MCU supported by FastArduino, even in ATtiny MCU, for which SPI is implemented with Universal Serial Interface (USI).

Note

USI does not allow full SPI support, contrarily to native SPI support of ATmega MCU. When differences exist, they are documented in the API.

Enumeration Type Documentation

ClockRate

enum class spi::ClockRate : uint8_t

strong

Define SPI clock rate as a divider of MCU clock frequency.

Note

this is not used in ATtiny.

See also

compute_clockrate()

Definition at line 47 of file spi.h.

DataOrder

enum class spi::DataOrder : uint8_t

strong

Bit ordering per byte.

Enumerator
MSB_FIRST	Most significant bit transferred first.
LSB_FIRST	Least significant bit transferred first. Note this is not available on ATtiny MCU.

Definition at line 87 of file spi.h.

Mode

enum class spi::Mode : uint8_t

strong

SPI transmission mode.

See also

https://en.wikipedia.org/wiki/Serial_Peripheral_Interface_Bus#Mode_numbers

Enumerator
MODE_0	SPI mode 0: CPOL = 0 and CPHA = 0.
MODE_1	SPI mode 1: CPOL = 0 and CPHA = 1.
MODE_2	SPI mode 2: CPOL = 1 and CPHA = 0. Note not available on ATtiny MCU.
MODE_3	SPI mode 3: CPOL = 1 and CPHA = 1. Note not available on ATtiny MCU.

Definition at line 109 of file spi.h.

ChipSelect

enum class spi::ChipSelect : uint8_t

strong

Active polarity of slave selection pin.

Enumerator
ACTIVE_LOW	Slave device is active when SS pin is low.
ACTIVE_HIGH	Slave device is active when SS pin is high.

Definition at line 137 of file spi.h.

Function Documentation

init()

void spi::init

(

)

This function must be called once in your program, before any use of an SPI device.

It simply sets up the pins used by SPI interface: MOSI, MISO, SCK.

Definition at line 20 of file spi.cpp.

compute_clockrate()

constexpr ClockRate spi::compute_clockrate ( uint32_t  frequency )

constexpr

Calculate ClockRate for the given frequency.

Computations done by this method will be performed at compile-time as long as all provided arguments are constants; this is important as this will help optimize code size and execution time.

See also

ClockRate

Definition at line 65 of file spi.h.