USART DMA Driver

Overview

Files
file	fsl_usart_dma.h

Data Structures
struct	usart_dma_handle_t
	UART DMA handle. More...

Typedefs
typedef void(*	usart_dma_transfer_callback_t )(USART_Type *base, usart_dma_handle_t *handle, status_t status, void *userData)
	UART transfer callback function. More...

DMA transactional
status_t	USART_TransferCreateHandleDMA (USART_Type *base, usart_dma_handle_t *handle, usart_dma_transfer_callback_t callback, void *userData, dma_handle_t *txDmaHandle, dma_handle_t *rxDmaHandle)
	Initializes the USART handle which is used in transactional functions. More...
status_t	USART_TransferSendDMA (USART_Type *base, usart_dma_handle_t *handle, usart_transfer_t *xfer)
	Sends data using DMA. More...
status_t	USART_TransferReceiveDMA (USART_Type *base, usart_dma_handle_t *handle, usart_transfer_t *xfer)
	Receives data using DMA. More...
void	USART_TransferAbortSendDMA (USART_Type *base, usart_dma_handle_t *handle)
	Aborts the sent data using DMA. More...
void	USART_TransferAbortReceiveDMA (USART_Type *base, usart_dma_handle_t *handle)
	Aborts the received data using DMA. More...
status_t	USART_TransferGetReceiveCountDMA (USART_Type *base, usart_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 _usart_dma_handle

Data Fields
USART_Type *	base
	UART peripheral base address. More...
usart_dma_transfer_callback_t	callback
	Callback function. More...
void *	userData
	UART callback function parameter. More...
size_t	rxDataSizeAll
	Size of the data to receive. More...
size_t	txDataSizeAll
	Size of the data to send out. More...
dma_handle_t *	txDmaHandle
	The DMA TX channel used. More...
dma_handle_t *	rxDmaHandle
	The DMA RX channel used. More...
volatile uint8_t	txState
	TX transfer state. More...
volatile uint8_t	rxState
	RX transfer state.

Field Documentation

USART_Type* usart_dma_handle_t::base

usart_dma_transfer_callback_t usart_dma_handle_t::callback

void* usart_dma_handle_t::userData

size_t usart_dma_handle_t::rxDataSizeAll

size_t usart_dma_handle_t::txDataSizeAll

dma_handle_t* usart_dma_handle_t::txDmaHandle

dma_handle_t* usart_dma_handle_t::rxDmaHandle

volatile uint8_t usart_dma_handle_t::txState

Typedef Documentation

typedef void(* usart_dma_transfer_callback_t)(USART_Type *base, usart_dma_handle_t *handle, status_t status, void *userData)

Function Documentation

status_t USART_TransferCreateHandleDMA	(	USART_Type *	base,
		usart_dma_handle_t *	handle,
		usart_dma_transfer_callback_t	callback,
		void *	userData,
		dma_handle_t *	txDmaHandle,
		dma_handle_t *	rxDmaHandle
	)

Parameters

base	USART peripheral base address.
handle	Pointer to usart_dma_handle_t structure.
callback	Callback function.
userData	User data.
txDmaHandle	User-requested DMA handle for TX DMA transfer.
rxDmaHandle	User-requested DMA handle for RX DMA transfer.

status_t USART_TransferSendDMA	(	USART_Type *	base,
		usart_dma_handle_t *	handle,
		usart_transfer_t *	xfer
	)

This function sends data using DMA. This is a non-blocking function, which returns right away. When all data is sent, the send callback function is called.

Parameters

base	USART peripheral base address.
handle	USART handle pointer.
xfer	USART DMA transfer structure. See usart_transfer_t.

Return values

kStatus_Success	if succeed, others failed.
kStatus_USART_TxBusy	Previous transfer on going.
kStatus_InvalidArgument	Invalid argument.

status_t USART_TransferReceiveDMA	(	USART_Type *	base,
		usart_dma_handle_t *	handle,
		usart_transfer_t *	xfer
	)

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	USART peripheral base address.
handle	Pointer to usart_dma_handle_t structure.
xfer	USART DMA transfer structure. See usart_transfer_t.

Return values

kStatus_Success	if succeed, others failed.
kStatus_USART_RxBusy	Previous transfer on going.
kStatus_InvalidArgument	Invalid argument.

void USART_TransferAbortSendDMA	(	USART_Type *	base,
		usart_dma_handle_t *	handle
	)

This function aborts send data using DMA.

Parameters

base	USART peripheral base address
handle	Pointer to usart_dma_handle_t structure

void USART_TransferAbortReceiveDMA	(	USART_Type *	base,
		usart_dma_handle_t *	handle
	)

This function aborts the received data using DMA.

Parameters

base	USART peripheral base address
handle	Pointer to usart_dma_handle_t structure

status_t USART_TransferGetReceiveCountDMA	(	USART_Type *	base,
		usart_dma_handle_t *	handle,
		uint32_t *	count
	)

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

Parameters

base	USART peripheral base address.
handle	USART 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;