DMIC DMA Driver

Overview

Files
file	fsl_dmic_dma.h

Data Structures
struct	dmic_transfer_t
	DMIC transfer structure. More...
struct	dmic_dma_handle_t
	DMIC DMA handle. More...

Typedefs
typedef void(*	dmic_dma_transfer_callback_t )(DMIC_Type *base, dmic_dma_handle_t *handle, status_t status, void *userData)
	DMIC transfer callback function. More...

Enumerations
enum	dmic_bitwidth_t {   kDMICBitWidth16Bits = 2U,   kDMICBitWidth32Bits = 4U }
	DMIC transfer structure. More...

DMA transactional
status_t	DMIC_TransferCreateHandleDMA (DMIC_Type *base, dmic_dma_handle_t *handle, dmic_dma_transfer_callback_t callback, void *userData, dma_handle_t *rxDmaHandle)
	Initializes the DMIC handle which is used in transactional functions. More...
static void	DMIC_TransferSetBitWidthDMA (DMIC_Type *base, dmic_dma_handle_t *handle, dmic_bitwidth_t width)
	Configure the transfer data width. More...
status_t	DMIC_TransferReceiveDMA (DMIC_Type *base, dmic_dma_handle_t *handle, dmic_transfer_t *xfer, uint32_t dmic_channel)
	Receives data using DMA. More...
void	DMIC_TransferAbortReceiveDMA (DMIC_Type *base, dmic_dma_handle_t *handle)
	Aborts the received data using DMA. More...
status_t	DMIC_TransferGetReceiveCountDMA (DMIC_Type *base, dmic_dma_handle_t *handle, uint32_t *count)
	Get the number of bytes that have been received. More...

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Data Structure Documentation

struct dmic_transfer_t

Data Fields
uint16_t *	data
	The buffer of data to be transfer. More...
size_t	dataSize
	The byte count to be transfer. More...

Field Documentation

uint16_t* dmic_transfer_t::data

size_t dmic_transfer_t::dataSize

struct _dmic_dma_handle

Data Fields
DMIC_Type *	base
	DMIC peripheral base address. More...
dma_handle_t *	rxDmaHandle
	The DMA RX channel used. More...
dmic_dma_transfer_callback_t	callback
	Callback function. More...
uint8_t	dataWidth
	Data bit width.
void *	userData
	DMIC callback function parameter. More...
size_t	transferSize
	Size of the data to receive. More...
volatile uint8_t	state
	Internal state of DMIC DMA transfer.

Field Documentation

DMIC_Type* dmic_dma_handle_t::base

dma_handle_t* dmic_dma_handle_t::rxDmaHandle

dmic_dma_transfer_callback_t dmic_dma_handle_t::callback

void* dmic_dma_handle_t::userData

size_t dmic_dma_handle_t::transferSize

Typedef Documentation

typedef void(* dmic_dma_transfer_callback_t)(DMIC_Type *base, dmic_dma_handle_t *handle, status_t status, void *userData)

Enumeration Type Documentation

enum dmic_bitwidth_t

Enumerator
kDMICBitWidth16Bits	16 bits mode.
kDMICBitWidth32Bits	32 bits mode.

Function Documentation

status_t DMIC_TransferCreateHandleDMA	(	DMIC_Type *	base,
		dmic_dma_handle_t *	handle,
		dmic_dma_transfer_callback_t	callback,
		void *	userData,
		dma_handle_t *	rxDmaHandle
	)

Parameters

base	DMIC peripheral base address.
handle	Pointer to dmic_dma_handle_t structure.
callback	Callback function.
userData	User data.
rxDmaHandle	User-requested DMA handle for RX DMA transfer.

static void DMIC_TransferSetBitWidthDMA ( DMIC_Type *  base, dmic_dma_handle_t *  handle, dmic_bitwidth_t  width  )

inlinestatic

This function is optional to users, the default data width is set to 16 bits if not call this fuction. DMIC only support 16 bits and 32 bits setting. As DMA cannot support 24 bits directly, please set to 32 bits while need a 24 bits data. In 32 bit mode, the MSB 8 bits always 0, as the register can only have 24 bits valid bits.

Parameters

base	DMIC peripheral base address.
handle	Pointer to usart_dma_handle_t structure.
width	DMIC width. See dmic_bitwidth_t.

Return values

kStatus_Success

status_t DMIC_TransferReceiveDMA	(	DMIC_Type *	base,
		dmic_dma_handle_t *	handle,
		dmic_transfer_t *	xfer,
		uint32_t	dmic_channel
	)

This function receives data using DMA. This is a non-blocking function, which returns right away. When all data is received, the receive callback function is called.

Parameters

base	DMIC peripheral base address.
handle	Pointer to usart_dma_handle_t structure.
xfer	DMIC DMA transfer structure. See dmic_transfer_t.
dmic_channel	DMIC channel

Return values

kStatus_Success

void DMIC_TransferAbortReceiveDMA	(	DMIC_Type *	base,
		dmic_dma_handle_t *	handle
	)

This function aborts the received data using DMA.

Parameters

base	DMIC peripheral base address
handle	Pointer to dmic_dma_handle_t structure

status_t DMIC_TransferGetReceiveCountDMA	(	DMIC_Type *	base,
		dmic_dma_handle_t *	handle,
		uint32_t *	count
	)

This function gets the number of bytes that have been received.

Parameters

base	DMIC peripheral base address.
handle	DMIC handle pointer.
count	Receive bytes count.

Return values

kStatus_NoTransferInProgress	No receive in progress.
kStatus_InvalidArgument	Parameter is invalid.
kStatus_Success	Get successfully through the parameter count;