General Description

High level interface for interacting with the memory-to-memory direct memory access (DMA).

This driver allows transferring data to/from the radio RAM from/to the main application RAM. For general-purpose DMA transfers, use the DMA driver.

Typedefs
typedef void(*	cyhal_m2m_event_callback_t) (void *callback_arg, cyhal_m2m_event_t event)
	Event handler for M2M interrupts.

Enumerations
enum	cyhal_m2m_rx_status_t { CYHAL_M2M_RX_DISABLED = 0x0 , CYHAL_M2M_RX_ACTIVE = 0x1 , CYHAL_M2M_RX_IDLE_WAIT = 0x2 , CYHAL_M2M_RX_STOPPED = 0x3 }
	Enum of M2M RX channel activity status. More...

enum	cyhal_m2m_event_t { CYHAL_M2M_NO_INTR = 0 , CYHAL_M2M_DESCRIPTOR_READ_ERROR = (1 << 0) , CYHAL_M2M_DATA_TRANSFER_ERROR = (1 << 1) , CYHAL_M2M_DESCRIPTOR_PROGRAM_ERROR = (1 << 2) , CYHAL_M2M_NO_DESCRIPTOR_ERROR = (1 << 3) , CYHAL_M2M_RX_CHANNEL_INTERRUPT = (1 << 4) , CYHAL_M2M_TX_CHANNEL_INTERRUPT = (1 << 5) }
	Flags enum of M2M events. More...

Functions
cy_rslt_t	cyhal_m2m_init (cyhal_m2m_t *obj, uint32_t rx_buffer_size)
	Initialize the M2M peripheral. More...

void	cyhal_m2m_free (cyhal_m2m_t *obj)
	Free the M2M object. More...

bool	cyhal_m2m_is_busy (cyhal_m2m_t *obj)
	Checks if the transfer has been triggered, but not yet complete (eg: is pending, blocked or running) More...

void	cyhal_m2m_register_callback (cyhal_m2m_t obj, cyhal_m2m_event_callback_t callback, void callback_arg)
	Register an M2M callback handler. More...

void	cyhal_m2m_enable_event (cyhal_m2m_t *obj, cyhal_m2m_event_t event, uint8_t intr_priority, bool enable)
	Configure M2M event enablement. More...

cy_rslt_t	cyhal_m2m_tx_send (cyhal_m2m_t obj, void buffer)
	Send M2M TX data packet. More...

void	cyhal_m2m_tx_release (cyhal_m2m_t *obj)
	Release next completed M2M TX data packet. More...

void	cyhal_m2m_rx_receive (cyhal_m2m_t obj, void rxd_handle, uint16_t *hwtag)
	Receive and read M2M RX data packet. More...

bool	cyhal_m2m_rx_prepare (cyhal_m2m_t *obj)
	Prepare M2M RX ring buffer. More...

cyhal_m2m_rx_status_t	cyhal_m2m_rx_status (cyhal_m2m_t *obj)
	M2M RX activity status. More...

cyhal_m2m_event_t	cyhal_m2m_intr_status (cyhal_m2m_t obj, bool signal_txdone)
	Read M2M TX and RX interrupt status. More...

Enumeration Type Documentation

◆ cyhal_m2m_rx_status_t

enum cyhal_m2m_rx_status_t

Enum of M2M RX channel activity status.

Enumerator
CYHAL_M2M_RX_DISABLED	Channel is disabled.
CYHAL_M2M_RX_ACTIVE	Channel is either waiting for data to transfer or is transferring data.
CYHAL_M2M_RX_IDLE_WAIT	Channel is waiting for a descriptor to be posted or is suspended.
CYHAL_M2M_RX_STOPPED	Channel is stopped because an error was detected.

◆ cyhal_m2m_event_t

enum cyhal_m2m_event_t

Flags enum of M2M events.

Multiple events can be enabled via cyhal_m2m_enable_event and the callback from cyhal_m2m_register_callback will be run to notify.

Enumerator
CYHAL_M2M_NO_INTR	No interrupt.
CYHAL_M2M_DESCRIPTOR_READ_ERROR	Descriptor read error.
CYHAL_M2M_DATA_TRANSFER_ERROR	Errors while transferring data to or from memory.
CYHAL_M2M_DESCRIPTOR_PROGRAM_ERROR	descriptor programming errors
CYHAL_M2M_NO_DESCRIPTOR_ERROR	Channel cannot process an incoming frame because no descriptors are available.
CYHAL_M2M_RX_CHANNEL_INTERRUPT	Interrupt from the RX channel.
CYHAL_M2M_TX_CHANNEL_INTERRUPT	Interrupt from the TX channel.

Function Documentation

◆ cyhal_m2m_init()

cy_rslt_t cyhal_m2m_init	(	cyhal_m2m_t *	obj,
		uint32_t	rx_buffer_size
	)

Initialize the M2M peripheral.

Parameters

[out]	obj	Pointer to an M2M object. The caller must allocate the memory for this object but the init function will initialize its contents.
[in]	rx_buffer_size	Size of the RX buffer.

Returns: The status of the init request

◆ cyhal_m2m_free()

void cyhal_m2m_free ( cyhal_m2m_t * obj )

Free the M2M object.

Freeing a M2M object while a transfer is in progress (cyhal_m2m_is_busy) is invalid.

Parameters

[in,out] obj The M2M object

◆ cyhal_m2m_is_busy()

bool cyhal_m2m_is_busy ( cyhal_m2m_t * obj )

Checks if the transfer has been triggered, but not yet complete (eg: is pending, blocked or running)

Parameters

[in] obj The M2M object

Returns: True if M2M channel is busy

◆ cyhal_m2m_register_callback()

void cyhal_m2m_register_callback	(	cyhal_m2m_t *	obj,
		cyhal_m2m_event_callback_t	callback,
		void *	callback_arg
	)

Register an M2M callback handler.

This function will be called when one of the events enabled by cyhal_m2m_enable_event occurs.

Parameters

[in]	obj	The M2M object
[in]	callback	The callback handler which will be invoked when an event triggers
[in]	callback_arg	Generic argument that will be provided to the callback when called

◆ cyhal_m2m_enable_event()

void cyhal_m2m_enable_event	(	cyhal_m2m_t *	obj,
		cyhal_m2m_event_t	event,
		uint8_t	intr_priority,
		bool	enable
	)

Configure M2M event enablement.

When an enabled event occurs, the function specified by cyhal_m2m_register_callback will be called.

Parameters

[in]	obj	The M2M object
[in]	event	The M2M event type
[in]	intr_priority	The priority for NVIC interrupt events. The priority from the most recent call will take precedence, i.e all events will have the same priority.
[in]	enable	True to turn on interrupts, False to turn off

◆ cyhal_m2m_tx_send()

cy_rslt_t cyhal_m2m_tx_send	(	cyhal_m2m_t *	obj,
		void *	buffer
	)

Send M2M TX data packet.

This function sends a TX data packet. WHD is expected to set the packet size and send the "data" with whd_buffer_t type. The buffer type is dependent on the network stack. For example for LWIP, it is structured as follows: p->payload = payload; //packet data p->len = len; //packet size

Parameters

[in]	obj	The M2M object
[in]	buffer	Data buffer to use in the packet transaction

Returns: The status of the tx operation

◆ cyhal_m2m_tx_release()

void cyhal_m2m_tx_release ( cyhal_m2m_t * obj )

Release next completed M2M TX data packet.

This function is used to free the TX data packet if TX error occurs.

Parameters

[in] obj The M2M object

◆ cyhal_m2m_rx_receive()

void cyhal_m2m_rx_receive	(	cyhal_m2m_t *	obj,
		void **	rxd_handle,
		uint16_t **	hwtag
	)

Receive and read M2M RX data packet.

This function reads the next available RX packet.

Parameters

[in]	obj	The M2M object
[out]	rxd_handle	RX packet handle
[out]	hwtag	Hardware tag used to read the frame header

◆ cyhal_m2m_rx_prepare()

bool cyhal_m2m_rx_prepare ( cyhal_m2m_t * obj )

Prepare M2M RX ring buffer.

Prepares the internal M2M RX buffer (allocated during initialization) for receiving RX data packets.

Parameters

[in] obj The M2M object

Returns: Success (true) or Failed (false)

◆ cyhal_m2m_rx_status()

cyhal_m2m_rx_status_t cyhal_m2m_rx_status ( cyhal_m2m_t * obj )

M2M RX activity status.

Parameters

[in] obj The M2M object

Returns: RX activity status

◆ cyhal_m2m_intr_status()

cyhal_m2m_event_t cyhal_m2m_intr_status	(	cyhal_m2m_t *	obj,
		bool *	signal_txdone
	)

Read M2M TX and RX interrupt status.

Reads the interrupt status for TX and RX channels.

Parameters

[in]	obj	The M2M object
[out]	signal_txdone	TX done state as signaled by the RX interrupt

Returns: Interrupt event status

General Description

Typedefs

Enumerations

Functions

Enumeration Type Documentation

◆ cyhal_m2m_rx_status_t

◆ cyhal_m2m_event_t

Function Documentation

◆ cyhal_m2m_init()

◆ cyhal_m2m_free()

◆ cyhal_m2m_is_busy()

◆ cyhal_m2m_register_callback()

◆ cyhal_m2m_enable_event()

◆ cyhal_m2m_tx_send()

◆ cyhal_m2m_tx_release()

◆ cyhal_m2m_rx_receive()

◆ cyhal_m2m_rx_prepare()

◆ cyhal_m2m_rx_status()

◆ cyhal_m2m_intr_status()