Detailed Description

Support for I2S Audio Protocol with different bit-depth, samplerate options Allows for master or slave, as well as freedom of selecting direction, and other behavior for each peripheral, and block.

DMA Transfer commands must use buffers located within non-cached memory or use cache maintenance To declare an unitialized global element in the DMA memory section: int32_t DSY_DMA_BUFFER_SECTOR my_buffer[96];

Callback functions will be called once per half of the buffer. In the above example, the callback function would be called once for every 48 samples.

Use SAI Handle like this:

SaiHandle::Config sai_config; sai_config.periph = SaiHandle::Config::Peripheral::SAI_1; sai_config.sr = SaiHandle::Config::SampleRate::SAI_48KHZ; sai_config.bit_depth = SaiHandle::Config::BitDepth::SAI_24BIT; sai_config.a_sync = SaiHandle::Config::Sync::MASTER; sai_config.b_sync = SaiHandle::Config::Sync::SLAVE; sai_config.a_dir = SaiHandle::Config::Direction::RECEIVE; sai_config.b_dir = SaiHandle::Config::Direction::TRANSMIT; sai_config.pin_config.fs = {DSY_GPIOE, 4}; sai_config.pin_config.mclk = {DSY_GPIOE, 2}; sai_config.pin_config.sck = {DSY_GPIOE, 5}; sai_config.pin_config.sa = {DSY_GPIOE, 6}; sai_config.pin_config.sb = {DSY_GPIOE, 3}; // Then Initialize SaiHandle sai; sai.Init(sai_config); // Now you can use it: sai.StartDma(. . .);

#include <sai.h>

Classes
struct	Config

Public Types
enum class	Result { OK , ERR }

typedef void(*	CallbackFunctionPtr) (int32_t in, int32_t out, size_t size)

Public Member Functions
	SaiHandle ()

	SaiHandle (const SaiHandle &other)=default

SaiHandle &	operator= (const SaiHandle &other)=default

Result	Init (const Config &config)

Result	DeInit ()

const Config &	GetConfig () const

Result	StartDma (int32_t buffer_rx, int32_t buffer_tx, size_t size, CallbackFunctionPtr callback)

Result	StopDma ()

float	GetSampleRate ()

size_t	GetBlockSize ()

float	GetBlockRate ()

size_t	GetOffset () const

bool	IsInitialized () const

Member Typedef Documentation

◆ CallbackFunctionPtr

typedef void(* daisy::SaiHandle::CallbackFunctionPtr) (int32_t *in, int32_t *out, size_t size)

Callback Function to be called when DMA transfer is complete and half complete. This callback is prepared however the data is transmitted/received from the device. For example, using an AK4556 the data will be interleaved 24bit MSB Justified

The hid/audio class will be allow for type conversions, de-interleaving, etc.

Member Enumeration Documentation

◆ Result

enum class daisy::SaiHandle::Result

strong

Return values for SAI functions

Enumerator
OK
ERR

Constructor & Destructor Documentation

◆ SaiHandle() [1/2]

daisy::SaiHandle::SaiHandle ( )

inline

◆ SaiHandle() [2/2]

daisy::SaiHandle::SaiHandle ( const SaiHandle & other )

default

Member Function Documentation

◆ DeInit()

Result daisy::SaiHandle::DeInit ( )

Deinitializes an SAI peripheral

◆ GetBlockRate()

float daisy::SaiHandle::GetBlockRate ( )

Returns the Block Rate of the current stream based on the size of the buffer passed in, and the current samplerate.

◆ GetBlockSize()

size_t daisy::SaiHandle::GetBlockSize ( )

Returns the number of samples per audio block Calculated as Buffer Size / 2 / number of channels

◆ GetConfig()

const Config & daisy::SaiHandle::GetConfig ( ) const

Returns the current configuration

◆ GetOffset()

size_t daisy::SaiHandle::GetOffset ( ) const

Returns the current offset within the SAI buffer, will be either 0 or size/2

◆ GetSampleRate()

float daisy::SaiHandle::GetSampleRate ( )

Returns the samplerate based on the current configuration

◆ Init()

Result daisy::SaiHandle::Init ( const Config & config )

Initializes an SAI peripheral

◆ IsInitialized()

bool daisy::SaiHandle::IsInitialized ( ) const

inline

◆ operator=()

SaiHandle & daisy::SaiHandle::operator= ( const SaiHandle & other )