daisy::SaiHandle¶

#include <sai.h>

Public Classes¶

	Name
struct	Config

Public Types¶

	Name
enum class	Result
typedef void()(int32_t in, int32_t *out, size_t size)	CallbackFunctionPtr

Public Functions¶

	Name
	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

Detailed Description¶

class daisy::SaiHandle;

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(. . .);

Public Types Documentation¶

enum Result¶

Enumerator	Value	Description
OK
ERR

Return values for SAI functions

typedef 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.

Public Functions Documentation¶

function SaiHandle¶

inline SaiHandle()

function SaiHandle¶

SaiHandle(
    const SaiHandle & other
) =default

function operator=¶

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

function Init¶

Result Init(
    const Config & config
)

Initializes an SAI peripheral

function DeInit¶

Result DeInit()

Deinitializes an SAI peripheral

function GetConfig¶

const Config & GetConfig() const

Returns the current configuration

function StartDma¶

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

Starts Rx and Tx in Circular Buffer Mode The callback will be called when half of the buffer is ready, and will handle size/2 samples per callback.

function StopDma¶

Result StopDma()

Stops the DMA stream for the SAI blocks in use.

function GetSampleRate¶

float GetSampleRate()

Returns the samplerate based on the current configuration

function GetBlockSize¶

size_t GetBlockSize()

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

function GetBlockRate¶

float GetBlockRate()

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

function GetOffset¶

size_t GetOffset() const

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

function IsInitialized¶

inline bool IsInitialized() const

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Updated on 2024-01-03 at 19:41:00 +0000