Time Division Multiplexed Audio Interface (TDM) peripheral driver. More...

Topics
	TDM peripheral driver configuration

Data Structures
struct	nrfx_tdm_clk_params_t
	Parameters used to describe TDM clock prescaling. More...

struct	nrfx_tdm_prescalers_t
	TDM prescalers structure. More...

struct	nrfx_tdm_buffers_t
	TDM transfer buffers structure. More...

struct	nrfx_tdm_config_t
	TDM driver configuration structure. More...

struct	nrfx_tdm_t
	TDM driver instance data structure. More...

Macros
#define	NRFX_TDM_DEFAULT_CONFIG(_sck_pin, _fsync_pin, _mck_pin, _sdout_pin, _sdin_pin)
	TDM driver default configuration.

#define	NRFX_TDM_NUM_OF_CHANNELS (TDM_CONFIG_CHANNEL_NUM_NUM_Max + 1)
	Maximum number of TDM channels.

#define	NRFX_TDM_MIN_TRANSFER_SIZE TDM_MIN_TRANSFER_SIZE
	Minimal transfer size of TDM buffer in 32-bit words.

#define	NRFX_TDM_MIN_TRANSFER_SIZE TDM_MIN_TRANSFER_SIZE
	Minimal transfer size of TDM buffer in 32-bit words.

#define	NRFX_TDM_STATUS_NEXT_BUFFERS_NEEDED (1UL << 0)
	TDM status flag indicating that the application must provide buffers that are to be used in the next part of the transfer. A call to nrfx_tdm_next_buffers_set must be done before the currently used buffers are completely processed (that is, the time remaining for supplying the next buffers depends on the used size of the buffers).

#define	NRFX_TDM_STATUS_TRANSFER_STOPPED (1UL << 1)
	TDM status flag indicating that The peripheral has been stopped and all buffers that were passed to the driver have been released.

#define	NRFX_TDM_INSTANCE(reg)
	Macro for creating a TDM driver instance.

Typedefs
typedef void(*	nrfx_tdm_data_handler_t) (nrfx_tdm_buffers_t const *p_released, uint32_t status)
	TDM driver data handler type.

Functions
int	nrfx_tdm_init (nrfx_tdm_t p_instance, nrfx_tdm_config_t const p_config, nrfx_tdm_data_handler_t handler)
	Function for initializing the TDM driver.

void	nrfx_tdm_uninit (nrfx_tdm_t *p_instance)
	Function for uninitializing the TDM driver.

bool	nrfx_tdm_init_check (nrfx_tdm_t const *p_instance)
	Function for checking if the TDM driver instance is initialized.

int	nrfx_tdm_reconfigure (nrfx_tdm_t p_instance, nrfx_tdm_config_t const p_config)
	Function for reconfiguring the TDM driver.

int	nrfx_tdm_start (nrfx_tdm_t p_instance, nrfx_tdm_buffers_t const p_initial_buffers)
	Function for starting the continuous TDM transfer.

int	nrfx_tdm_next_buffers_set (nrfx_tdm_t p_instance, nrfx_tdm_buffers_t const p_buffers)
	Function for supplying the buffers to be used in the next part of the transfer.

void	nrfx_tdm_stop (nrfx_tdm_t *p_instance, bool abort)
	Function for stopping the TDM transfer.

int	nrfx_tdm_prescalers_calc (nrfx_tdm_clk_params_t const clk_params, nrfx_tdm_prescalers_t prescalers)
	Function for calculating TDM clock prescaler values.

void	nrfx_tdm_irq_handler (nrfx_tdm_t *p_instance)
	Driver interrupt handler.

Detailed Description

Time Division Multiplexed Audio Interface (TDM) peripheral driver.

Macro Definition Documentation

◆ NRFX_TDM_DEFAULT_CONFIG

#define NRFX_TDM_DEFAULT_CONFIG	(	_sck_pin,
		_fsync_pin,
		_mck_pin,
		_sdout_pin,
		_sdin_pin )

Value:

{                                                                                      \
    .sck_pin         = _sck_pin,                                                       \
    .fsync_pin       = _fsync_pin,                                                     \
    .mck_pin         = _mck_pin,                                                       \
    .sdout_pin       = _sdout_pin,                                                     \
    .sdin_pin        = _sdin_pin,                                                      \
    .irq_priority    = NRFX_TDM_DEFAULT_CONFIG_IRQ_PRIORITY,                           \
    .mode            = NRF_TDM_MODE_MASTER,                                            \
    .alignment       = NRF_TDM_ALIGN_LEFT,                                             \
    .sample_width    = NRF_TDM_SWIDTH_16BIT,                                           \
    .rx_channel_mask = NRF_TDM_CHANNEL_RX0_MASK,                                       \
    .tx_channel_mask = NRF_TDM_CHANNEL_TX0_MASK,                                       \
    .channel_number  = 2,                                                              \
    .channel_delay   = NRF_TDM_CHANNEL_DELAY_1CK,                                      \
    .sck_polarity    = NRF_TDM_POLARITY_POSEDGE,                                       \
    .fsync_polarity  = NRF_TDM_POLARITY_NEGEDGE,                                       \
    .fsync_duration  = NRFX_TDM_DEFAULT_FSYNC_DURATION,                                \
    .ors             = 0,                                                              \
    .mck_src         = NRF_TDM_SRC_PCLK32M,                                            \
    .sck_src         = NRF_TDM_SRC_PCLK32M,                                            \
    .prescalers      =                                                                 \
    {                                                                                  \
        .mck_div     = NRF_TDM_MCK_DIV_8,                                              \
        .sck_div     = NRF_TDM_SCK_DIV_8,                                              \
    },                                                                                 \
}

TDM driver default configuration.

This configuration sets up TDM with the following options:

Master mode
Left alignment
16 bit sample width
One RX channel enabled
One TX channel enabled
Delay of one clock pulse
TX on the falling edge of SCK, RX on the rising edge of SCK
Frame starts at falling edge of FSYNC.
Zeros sent as over-read
PCLK32M clock source
MCK frequency divider equal to 8
SCK frequency divider equal to 8

Parameters

[in]	_sck_pin	Serial clock pin number.
[in]	_fsync_pin	Frame Synchronization pin number.
[in]	_mck_pin	Master clock pin number.
[in]	_sdout_pin	Serial Data Output pin number.
[in]	_sdin_pin	Serial Data Input pin number.

◆ NRFX_TDM_INSTANCE

#define NRFX_TDM_INSTANCE ( reg )

Value:

{                                 \
    .p_reg = (NRF_TDM_Type *)reg, \
    .cb = {0},                    \
}

Macro for creating a TDM driver instance.

◆ NRFX_TDM_MIN_TRANSFER_SIZE [1/2]

#define NRFX_TDM_MIN_TRANSFER_SIZE TDM_MIN_TRANSFER_SIZE

Minimal transfer size of TDM buffer in 32-bit words.

Minimum TDM transfer size in bytes.

◆ NRFX_TDM_MIN_TRANSFER_SIZE [2/2]

#define NRFX_TDM_MIN_TRANSFER_SIZE TDM_MIN_TRANSFER_SIZE

Minimal transfer size of TDM buffer in 32-bit words.

Minimum TDM transfer size in bytes.

Typedef Documentation

◆ nrfx_tdm_data_handler_t

typedef void(* nrfx_tdm_data_handler_t) (nrfx_tdm_buffers_t const *p_released, uint32_t status)

TDM driver data handler type.

A data handling function of this type must be specified during the initialization of the driver. The driver will call this function when it finishes transfer using buffers passed to it by the application, and when it needs to be provided with buffers for the next part of the transfer.

Note: The p_released pointer passed to this function is temporary and will be invalid after the function returns, hence it cannot be stored and used later. If needed, the pointed content (that is, buffers pointers) must be copied instead.

Parameters

[in] p_released Pointer to a structure with pointers to buffers passed previously to the driver that will no longer be accessed by it (they can be now safely released or used for another purpose, in particular for a next part of the transfer). This pointer will be NULL if the application did not supply the buffers for the next part of the transfer (via a call to nrfx_tdm_next_buffers_set) since the previous time the data handler signaled such need. This means that data corruption occurred (the previous buffers are used for the second time) and no buffers can be released at the moment. Both pointers in this structure are NULL when the handler is called for the first time after a transfer is started, because no data has been transferred yet at this point. In all successive calls, the pointers specify what has been sent (TX) and what has been received (RX) in the part of the transfer that has just been completed (provided that a given direction is enabled, see nrfx_tdm_start).

Note: Since the peripheral is stopped asynchronously, buffers that are released after the call to nrfx_tdm_stop are not used entirely. In this case, only a part (if any) of the TX buffer has been actually transmitted and only a part (if any) of the RX buffer is filled with received data.

Parameters

[in]

status

Bit field describing the current status of the transfer. It can be 0 or a combination of the following flags:

NRFX_TDM_STATUS_NEXT_BUFFERS_NEEDED
NRFX_TDM_STATUS_TRANSFER_STOPPED

Function Documentation

◆ nrfx_tdm_init()

int nrfx_tdm_init	(	nrfx_tdm_t *	p_instance,
		nrfx_tdm_config_t const *	p_config,
		nrfx_tdm_data_handler_t	handler )

Function for initializing the TDM driver.

Parameters

[in]	p_instance	Pointer to the driver instance structure.
[in]	p_config	Pointer to the structure with the initial configuration.
[in]	handler	Data handler provided by the user.

Return values

0	Initialization was successful.
-EALREADY	The driver is already initialized.
-EINVAL	The requested combination of configuration options is not allowed by the TDM peripheral.

◆ nrfx_tdm_init_check()

bool nrfx_tdm_init_check ( nrfx_tdm_t const * p_instance )

Function for checking if the TDM driver instance is initialized.

Parameters

[in] p_instance Pointer to the driver instance structure.

Return values

true	Instance is already initialized.
false	Instance is not initialized.

◆ nrfx_tdm_irq_handler()

void nrfx_tdm_irq_handler ( nrfx_tdm_t * p_instance )

Driver interrupt handler.

Parameters

[in] p_instance Pointer to the driver instance structure.

◆ nrfx_tdm_next_buffers_set()

int nrfx_tdm_next_buffers_set	(	nrfx_tdm_t *	p_instance,
		nrfx_tdm_buffers_t const *	p_buffers )

Function for supplying the buffers to be used in the next part of the transfer.

The application must call this function when the data handler receives NRFX_TDM_STATUS_NEXT_BUFFERS_NEEDED in the status parameter. The call can be done immediately from the data handler function or later, but it has to be done before the TDM peripheral finishes processing the buffers supplied previously. Otherwise, data corruption will occur.

Parameters

[in]	p_instance	Pointer to the driver instance structure.
[in]	p_buffers	Pointer to a structure specifying the buffers to be used in the upcoming part of the transfer.

Return values

0	If the operation was successful.
-EINPROGRESS	If the buffers were already supplied or the peripheral is currently being stopped.
-EINVAL	Required buffers were not provided or the provided transfer length is too short.
-EACCES	The provided buffers are not placed in the Data RAM region.

◆ nrfx_tdm_prescalers_calc()

int nrfx_tdm_prescalers_calc	(	nrfx_tdm_clk_params_t const *	clk_params,
		nrfx_tdm_prescalers_t *	prescalers )

Function for calculating TDM clock prescaler values.

Call this function to find suitable value for prescalers in nrfx_tdm_config_t structure.

If prescaler calculation for a specific clock is to be skipped, its desired frequency should be set to 0.

Application must ensure that requested clock frequency can be achieved using its base clock frequency.

Parameters

[in]	clk_params	Parameters used to describe clock prescaling.
[out]	prescalers	Prescaler structure pointer to be filled with prescaler values.

Return values

0	Suitable prescaler values were found for both clocks.
-EINVAL	No suitable prescaler values were found for either of the clocks.

◆ nrfx_tdm_reconfigure()

int nrfx_tdm_reconfigure	(	nrfx_tdm_t *	p_instance,
		nrfx_tdm_config_t const *	p_config )

Function for reconfiguring the TDM driver.

Parameters

[in]	p_instance	Pointer to the driver instance structure.
[in]	p_config	Pointer to the structure with the configuration.

Return values

0	Reconfiguration was successful.
-EINPROGRESS	The driver is uninitialized.
-EINVAL	The requested combination of configuration options is not allowed by the TDM peripheral.

◆ nrfx_tdm_start()

int nrfx_tdm_start	(	nrfx_tdm_t *	p_instance,
		nrfx_tdm_buffers_t const *	p_initial_buffers )

Function for starting the continuous TDM transfer.

The TDM data transfer can be performed in one of three modes: RX (reception) only, TX (transmission) only, or in both directions simultaneously. The mode is selected by specifying a proper buffer for a given direction in the call to this function or by passing NULL instead if this direction is to be disabled.

The length of the buffer (which is a common value for RX and TX if both directions are enabled) is specified in 32-bit words. One 32-bit memory word can either contain four 8-bit samples, two 16-bit samples, or one right-aligned 24-bit sample sign-extended to a 32-bit value. For a detailed memory mapping for different supported configurations, see the Product Specification.

Note: Peripherals using EasyDMA (including TDM) require the transfer buffers to be placed in the Data RAM region. If this condition is not met, this function will fail with the error code -EACCES.

Parameters

[in]	p_instance	Pointer to the driver instance structure.
[in]	p_initial_buffers	Pointer to a structure specifying the buffers to be used in the initial part of the transfer (buffers for all consecutive parts are provided through the data handler).

Return values

0	The operation was successful.
-EINPROGRESS	The driver has not been initialized.
-EALREADY	Transfer has already been already started.
-EINVAL	No buffers were provided or the provided transfer length is too short.
-EACCES	The provided buffers are not placed in the Data RAM region.

◆ nrfx_tdm_stop()

void nrfx_tdm_stop	(	nrfx_tdm_t *	p_instance,
		bool	abort )

Function for stopping the TDM transfer.

Parameters

[in]	p_instance	Pointer to the driver instance structure.
[in]	abort	True if transfer is to be stopped immediately, false if transfer is to be stopped only after currently processed buffers are filled.

◆ nrfx_tdm_uninit()

void nrfx_tdm_uninit ( nrfx_tdm_t * p_instance )

Function for uninitializing the TDM driver.

Parameters

[in] p_instance Pointer to the driver instance structure.

Topics

Data Structures

Macros

Typedefs

Functions

Detailed Description

Macro Definition Documentation

◆ NRFX_TDM_DEFAULT_CONFIG

◆ NRFX_TDM_INSTANCE

◆ NRFX_TDM_MIN_TRANSFER_SIZE [1/2]

◆ NRFX_TDM_MIN_TRANSFER_SIZE [2/2]

Typedef Documentation

◆ nrfx_tdm_data_handler_t

Function Documentation

◆ nrfx_tdm_init()

◆ nrfx_tdm_init_check()

◆ nrfx_tdm_irq_handler()

◆ nrfx_tdm_next_buffers_set()

◆ nrfx_tdm_prescalers_calc()

◆ nrfx_tdm_reconfigure()

◆ nrfx_tdm_start()

◆ nrfx_tdm_stop()

◆ nrfx_tdm_uninit()