Overview

The MCUXpresso SDK provides a peripheral driver for the Microphone Interface (PDM) module of MCUXpresso SDK devices.

PDM driver includes functional APIs and transactional APIs.

Functional APIs target low-level APIs. Functional APIs can be used for PDM initialization, configuration, and operation for the optimization and customization purpose. Using the functional API requires the knowledge of the PDM peripheral and how to organize functional APIs to meet the application requirements. All functional API use the peripheral base address as the first parameter. PDM functional operation groups provide the functional API set.

Transactional APIs target high-level APIs. Transactional APIs can be used to enable the peripheral and in the application if the code size and performance of transactional APIs satisfy the requirements. If the code size and performance are a critical requirement, see the transactional API implementation and write a custom code. Initialize the handle by calling the PDM_TransferCreateHandle() API.

Transactional APIs support asynchronous transfer. This means that the functions PDM_TransferReceiveNonBlocking() set up the interrupt for data transfer. When the transfer completes, the upper layer is notified through a callback function with kStatus_PDM_Idle status.

Typical use case

PDM receive using an interrupt method

Refer to the driver examples codes located at <SDK_ROOT>/boards/<BOARD>/driver_examples/pdm_interrupt

PDM receive using a SDMA method

Refer to the driver examples codes located at <SDK_ROOT>/boards/<BOARD>/driver_examples/pdm/pdm_sdma_transfer

PDM receive using a EDMA method

Refer to the driver examples codes located at <SDK_ROOT>/boards/<BOARD>/driver_examples/pdm/pdm_edma_transfer Refer to the driver examples codes located at <SDK_ROOT>/boards/<BOARD>/driver_examples/pdm/pdm_sai_edma Refer to the driver examples codes located at <SDK_ROOT>/boards/<BOARD>/driver_examples/pdm/pdm_sai_multi_channel_edma

PDM receive using a transactional method

Refer to the driver examples codes located at <SDK_ROOT>/boards/<BOARD>/driver_examples/pdm/pdm_interrupt_transfer

Data Structures
struct	pdm_channel_config_t
	PDM channel configurations. More...

struct	pdm_config_t
	PDM user configuration structure. More...

struct	pdm_hwvad_config_t
	PDM voice activity detector user configuration structure. More...

struct	pdm_hwvad_noise_filter_t
	PDM voice activity detector noise filter user configuration structure. More...

struct	pdm_hwvad_zero_cross_detector_t
	PDM voice activity detector zero cross detector configuration structure. More...

struct	pdm_transfer_t
	PDM SDMA transfer structure. More...

struct	pdm_handle_t
	PDM handle structure. More...

Macros
#define	PDM_XFER_QUEUE_SIZE (4U)
	PDM XFER QUEUE SIZE.

Typedefs
typedef void(*	pdm_transfer_callback_t )(PDM_Type base, pdm_handle_t handle, status_t status, void *userData)
	PDM transfer callback prototype.

Enumerations
enum	{ kStatus_PDM_Busy = MAKE_STATUS(kStatusGroup_PDM, 0), kStatus_PDM_CLK_LOW = MAKE_STATUS(kStatusGroup_PDM, 1), kStatus_PDM_FIFO_ERROR = MAKE_STATUS(kStatusGroup_PDM, 2), kStatus_PDM_QueueFull = MAKE_STATUS(kStatusGroup_PDM, 3), kStatus_PDM_Idle = MAKE_STATUS(kStatusGroup_PDM, 4), kStatus_PDM_Output_ERROR = MAKE_STATUS(kStatusGroup_PDM, 5), kStatus_PDM_ChannelConfig_Failed = MAKE_STATUS(kStatusGroup_PDM, 6) }
	PDM return status. More...

enum	_pdm_interrupt_enable { kPDM_ErrorInterruptEnable = PDM_CTRL_1_ERREN_MASK, kPDM_FIFOInterruptEnable = PDM_CTRL_1_DISEL(2U) }
	The PDM interrupt enable flag. More...

enum	_pdm_internal_status { kPDM_StatusDfBusyFlag = (int)PDM_STAT_BSY_FIL_MASK, kPDM_StatusFIRFilterReady = PDM_STAT_FIR_RDY_MASK, kPDM_StatusFrequencyLow = PDM_STAT_LOWFREQF_MASK, kPDM_StatusCh0FifoDataAvaliable = PDM_STAT_CH0F_MASK, kPDM_StatusCh1FifoDataAvaliable = PDM_STAT_CH1F_MASK, kPDM_StatusCh2FifoDataAvaliable = PDM_STAT_CH2F_MASK, kPDM_StatusCh3FifoDataAvaliable = PDM_STAT_CH3F_MASK, kPDM_StatusCh4FifoDataAvaliable = PDM_STAT_CH4F_MASK, kPDM_StatusCh5FifoDataAvaliable = PDM_STAT_CH5F_MASK, kPDM_StatusCh6FifoDataAvaliable = PDM_STAT_CH6F_MASK, kPDM_StatusCh7FifoDataAvaliable = PDM_STAT_CH7F_MASK }
	The PDM status. More...

enum	_pdm_channel_enable_mask { kPDM_EnableChannel0 = PDM_STAT_CH0F_MASK, kPDM_EnableChannel1 = PDM_STAT_CH1F_MASK, kPDM_EnableChannel2 = PDM_STAT_CH2F_MASK, kPDM_EnableChannel3 = PDM_STAT_CH3F_MASK, kPDM_EnableChannel4 = PDM_STAT_CH4F_MASK, kPDM_EnableChannel5 = PDM_STAT_CH5F_MASK, kPDM_EnableChannel6 = PDM_STAT_CH6F_MASK, kPDM_EnableChannel7 = PDM_STAT_CH7F_MASK }
	PDM channel enable mask. More...

enum	_pdm_fifo_status { kPDM_FifoStatusUnderflowCh0 = PDM_FIFO_STAT_FIFOUND0_MASK, kPDM_FifoStatusUnderflowCh1 = PDM_FIFO_STAT_FIFOUND1_MASK, kPDM_FifoStatusUnderflowCh2 = PDM_FIFO_STAT_FIFOUND2_MASK, kPDM_FifoStatusUnderflowCh3 = PDM_FIFO_STAT_FIFOUND3_MASK, kPDM_FifoStatusUnderflowCh4 = PDM_FIFO_STAT_FIFOUND4_MASK, kPDM_FifoStatusUnderflowCh5 = PDM_FIFO_STAT_FIFOUND5_MASK, kPDM_FifoStatusUnderflowCh6 = PDM_FIFO_STAT_FIFOUND6_MASK, kPDM_FifoStatusUnderflowCh7 = PDM_FIFO_STAT_FIFOUND6_MASK, kPDM_FifoStatusOverflowCh0 = PDM_FIFO_STAT_FIFOOVF0_MASK, kPDM_FifoStatusOverflowCh1 = PDM_FIFO_STAT_FIFOOVF1_MASK, kPDM_FifoStatusOverflowCh2 = PDM_FIFO_STAT_FIFOOVF2_MASK, kPDM_FifoStatusOverflowCh3 = PDM_FIFO_STAT_FIFOOVF3_MASK, kPDM_FifoStatusOverflowCh4 = PDM_FIFO_STAT_FIFOOVF4_MASK, kPDM_FifoStatusOverflowCh5 = PDM_FIFO_STAT_FIFOOVF5_MASK, kPDM_FifoStatusOverflowCh6 = PDM_FIFO_STAT_FIFOOVF6_MASK, kPDM_FifoStatusOverflowCh7 = PDM_FIFO_STAT_FIFOOVF7_MASK }
	The PDM fifo status. More...

enum	_pdm_range_status { kPDM_RangeStatusUnderFlowCh0 = PDM_RANGE_STAT_RANGEUNF0_MASK, kPDM_RangeStatusUnderFlowCh1 = PDM_RANGE_STAT_RANGEUNF1_MASK, kPDM_RangeStatusUnderFlowCh2 = PDM_RANGE_STAT_RANGEUNF2_MASK, kPDM_RangeStatusUnderFlowCh3 = PDM_RANGE_STAT_RANGEUNF3_MASK, kPDM_RangeStatusUnderFlowCh4 = PDM_RANGE_STAT_RANGEUNF4_MASK, kPDM_RangeStatusUnderFlowCh5 = PDM_RANGE_STAT_RANGEUNF5_MASK, kPDM_RangeStatusUnderFlowCh6 = PDM_RANGE_STAT_RANGEUNF6_MASK, kPDM_RangeStatusUnderFlowCh7 = PDM_RANGE_STAT_RANGEUNF7_MASK, kPDM_RangeStatusOverFlowCh0 = PDM_RANGE_STAT_RANGEOVF0_MASK, kPDM_RangeStatusOverFlowCh1 = PDM_RANGE_STAT_RANGEOVF1_MASK, kPDM_RangeStatusOverFlowCh2 = PDM_RANGE_STAT_RANGEOVF2_MASK, kPDM_RangeStatusOverFlowCh3 = PDM_RANGE_STAT_RANGEOVF3_MASK, kPDM_RangeStatusOverFlowCh4 = PDM_RANGE_STAT_RANGEOVF4_MASK, kPDM_RangeStatusOverFlowCh5 = PDM_RANGE_STAT_RANGEOVF5_MASK, kPDM_RangeStatusOverFlowCh6 = PDM_RANGE_STAT_RANGEOVF6_MASK, kPDM_RangeStatusOverFlowCh7 = PDM_RANGE_STAT_RANGEOVF7_MASK }
	The PDM output status. More...

enum	pdm_dc_remover_t { kPDM_DcRemoverCutOff21Hz = 0U, kPDM_DcRemoverCutOff83Hz = 1U, kPDM_DcRemoverCutOff152Hz = 2U, kPDM_DcRemoverBypass = 3U }
	PDM DC remover configurations. More...

enum	pdm_df_quality_mode_t { kPDM_QualityModeMedium = 0U, kPDM_QualityModeHigh = 1U, kPDM_QualityModeLow = 7U, kPDM_QualityModeVeryLow0 = 6U, kPDM_QualityModeVeryLow1 = 5U, kPDM_QualityModeVeryLow2 = 4U }
	PDM decimation filter quality mode. More...

enum	_pdm_qulaity_mode_k_factor { kPDM_QualityModeHighKFactor = 1U, kPDM_QualityModeMediumKFactor = 2U, kPDM_QualityModeLowKFactor = 4U, kPDM_QualityModeVeryLow2KFactor = 8U }
	PDM quality mode K factor. More...

enum	pdm_df_output_gain_t { kPDM_DfOutputGain0 = 0U, kPDM_DfOutputGain1 = 1U, kPDM_DfOutputGain2 = 2U, kPDM_DfOutputGain3 = 3U, kPDM_DfOutputGain4 = 4U, kPDM_DfOutputGain5 = 5U, kPDM_DfOutputGain6 = 6U, kPDM_DfOutputGain7 = 7U, kPDM_DfOutputGain8 = 8U, kPDM_DfOutputGain9 = 9U, kPDM_DfOutputGain10 = 0xAU, kPDM_DfOutputGain11 = 0xBU, kPDM_DfOutputGain12 = 0xCU, kPDM_DfOutputGain13 = 0xDU, kPDM_DfOutputGain14 = 0xEU, kPDM_DfOutputGain15 = 0xFU }
	PDM decimation filter output gain. More...

enum	_pdm_data_width { kPDM_DataWwidth24 = 3U, kPDM_DataWwidth32 = 4U }
	PDM data width. More...

enum	_pdm_hwvad_interrupt_enable { kPDM_HwvadErrorInterruptEnable = PDM_VAD0_CTRL_1_VADERIE_MASK, kPDM_HwvadInterruptEnable = PDM_VAD0_CTRL_1_VADIE_MASK }
	PDM voice activity detector interrupt type. More...

enum	_pdm_hwvad_int_status { kPDM_HwvadStatusInputSaturation = PDM_VAD0_STAT_VADINSATF_MASK, kPDM_HwvadStatusVoiceDetectFlag = PDM_VAD0_STAT_VADIF_MASK }
	The PDM hwvad interrupt status flag. More...

enum	pdm_hwvad_hpf_config_t { kPDM_HwvadHpfBypassed = 0x0U, kPDM_HwvadHpfCutOffFreq1750Hz = 0x1U, kPDM_HwvadHpfCutOffFreq215Hz = 0x2U, kPDM_HwvadHpfCutOffFreq102Hz = 0x3U }
	High pass filter configure cut-off frequency. More...

enum	pdm_hwvad_filter_status_t { kPDM_HwvadInternalFilterNormalOperation = 0U, kPDM_HwvadInternalFilterInitial = PDM_VAD0_CTRL_1_VADST10_MASK }
	HWVAD internal filter status. More...

enum	pdm_hwvad_zcd_result_t { kPDM_HwvadResultOREnergyBasedDetection, kPDM_HwvadResultANDEnergyBasedDetection }
	PDM voice activity detector zero cross detector result. More...

Driver version
#define	FSL_PDM_DRIVER_VERSION (MAKE_VERSION(2, 5, 0))
	Version 2.5.0.

Initialization and deinitialization
void	PDM_Init (PDM_Type base, const pdm_config_t config)
	Initializes the PDM peripheral. More...

void	PDM_Deinit (PDM_Type *base)
	De-initializes the PDM peripheral. More...

static void	PDM_Reset (PDM_Type *base)
	Resets the PDM module. More...

static void	PDM_Enable (PDM_Type *base, bool enable)
	Enables/disables PDM interface. More...

static void	PDM_EnableDoze (PDM_Type *base, bool enable)
	Enables/disables DOZE. More...

static void	PDM_EnableDebugMode (PDM_Type *base, bool enable)
	Enables/disables debug mode for PDM. More...

static void	PDM_EnableInDebugMode (PDM_Type *base, bool enable)
	Enables/disables PDM interface in debug mode. More...

static void	PDM_EnterLowLeakageMode (PDM_Type *base, bool enable)
	Enables/disables PDM interface disable/Low Leakage mode. More...

static void	PDM_EnableChannel (PDM_Type *base, uint8_t channel, bool enable)
	Enables/disables the PDM channel. More...

void	PDM_SetChannelConfig (PDM_Type base, uint32_t channel, const pdm_channel_config_t config)
	PDM one channel configurations. More...

status_t	PDM_SetSampleRateConfig (PDM_Type *base, uint32_t sourceClock_HZ, uint32_t sampleRate_HZ)
	PDM set sample rate. More...

status_t	PDM_SetSampleRate (PDM_Type *base, uint32_t enableChannelMask, pdm_df_quality_mode_t qualityMode, uint8_t osr, uint32_t clkDiv)
	PDM set sample rate. More...

uint32_t	PDM_GetInstance (PDM_Type *base)
	Get the instance number for PDM. More...

Status
static uint32_t	PDM_GetStatus (PDM_Type *base)
	Gets the PDM internal status flag. More...

static uint32_t	PDM_GetFifoStatus (PDM_Type *base)
	Gets the PDM FIFO status flag. More...

static uint32_t	PDM_GetRangeStatus (PDM_Type *base)
	Gets the PDM Range status flag. More...

static void	PDM_ClearStatus (PDM_Type *base, uint32_t mask)
	Clears the PDM Tx status. More...

static void	PDM_ClearFIFOStatus (PDM_Type *base, uint32_t mask)
	Clears the PDM Tx status. More...

static void	PDM_ClearRangeStatus (PDM_Type *base, uint32_t mask)
	Clears the PDM range status. More...

Interrupts
void	PDM_EnableInterrupts (PDM_Type *base, uint32_t mask)
	Enables the PDM interrupt requests. More...

static void	PDM_DisableInterrupts (PDM_Type *base, uint32_t mask)
	Disables the PDM interrupt requests. More...

DMA Control
static void	PDM_EnableDMA (PDM_Type *base, bool enable)
	Enables/disables the PDM DMA requests. More...

static uint32_t	PDM_GetDataRegisterAddress (PDM_Type *base, uint32_t channel)
	Gets the PDM data register address. More...

Bus Operations
void	PDM_ReadFifo (PDM_Type base, uint32_t startChannel, uint32_t channelNums, void buffer, size_t size, uint32_t dataWidth)
	PDM read fifo. More...

static uint32_t	PDM_ReadData (PDM_Type *base, uint32_t channel)
	Reads data from the PDM FIFO. More...

Voice Activity Detector
void	PDM_SetHwvadConfig (PDM_Type base, const pdm_hwvad_config_t config)
	Configure voice activity detector. More...

static void	PDM_ForceHwvadOutputDisable (PDM_Type *base, bool enable)
	PDM hwvad force output disable. More...

static void	PDM_ResetHwvad (PDM_Type *base)
	PDM hwvad reset. More...

static void	PDM_EnableHwvad (PDM_Type *base, bool enable)
	Enable/Disable Voice activity detector. More...

static void	PDM_EnableHwvadInterrupts (PDM_Type *base, uint32_t mask)
	Enables the PDM Voice Detector interrupt requests. More...

static void	PDM_DisableHwvadInterrupts (PDM_Type *base, uint32_t mask)
	Disables the PDM Voice Detector interrupt requests. More...

static void	PDM_ClearHwvadInterruptStatusFlags (PDM_Type *base, uint32_t mask)
	Clears the PDM voice activity detector status flags. More...

static uint32_t	PDM_GetHwvadInterruptStatusFlags (PDM_Type *base)
	Clears the PDM voice activity detector status flags. More...

static uint32_t	PDM_GetHwvadInitialFlag (PDM_Type *base)
	Get the PDM voice activity detector initial flags. More...

static uint32_t	PDM_GetHwvadVoiceDetectedFlag (PDM_Type *base)
	Get the PDM voice activity detector voice detected flags. More...

static void	PDM_EnableHwvadSignalFilter (PDM_Type *base, bool enable)
	Enables/disables voice activity detector signal filter. More...

void	PDM_SetHwvadSignalFilterConfig (PDM_Type *base, bool enableMaxBlock, uint32_t signalGain)
	Configure voice activity detector signal filter. More...

void	PDM_SetHwvadNoiseFilterConfig (PDM_Type base, const pdm_hwvad_noise_filter_t config)
	Configure voice activity detector noise filter. More...

static void	PDM_EnableHwvadZeroCrossDetector (PDM_Type *base, bool enable)
	Enables/disables voice activity detector zero cross detector. More...

void	PDM_SetHwvadZeroCrossDetectorConfig (PDM_Type base, const pdm_hwvad_zero_cross_detector_t config)
	Configure voice activity detector zero cross detector. More...

static uint16_t	PDM_GetNoiseData (PDM_Type *base)
	Reads noise data. More...

static void	PDM_SetHwvadInternalFilterStatus (PDM_Type *base, pdm_hwvad_filter_status_t status)
	set hwvad internal filter status . More...

void	PDM_SetHwvadInEnvelopeBasedMode (PDM_Type base, const pdm_hwvad_config_t hwvadConfig, const pdm_hwvad_noise_filter_t noiseConfig, const pdm_hwvad_zero_cross_detector_t zcdConfig, uint32_t signalGain)
	set HWVAD in envelope based mode . More...

void	PDM_SetHwvadInEnergyBasedMode (PDM_Type base, const pdm_hwvad_config_t hwvadConfig, const pdm_hwvad_noise_filter_t noiseConfig, const pdm_hwvad_zero_cross_detector_t zcdConfig, uint32_t signalGain)
	brief set HWVAD in energy based mode . More...

Transactional
void	PDM_TransferCreateHandle (PDM_Type base, pdm_handle_t handle, pdm_transfer_callback_t callback, void *userData)
	Initializes the PDM handle. More...

status_t	PDM_TransferSetChannelConfig (PDM_Type base, pdm_handle_t handle, uint32_t channel, const pdm_channel_config_t *config, uint32_t format)
	PDM set channel transfer config. More...

status_t	PDM_TransferReceiveNonBlocking (PDM_Type base, pdm_handle_t handle, pdm_transfer_t *xfer)
	Performs an interrupt non-blocking receive transfer on PDM. More...

void	PDM_TransferAbortReceive (PDM_Type base, pdm_handle_t handle)
	Aborts the current IRQ receive. More...

void	PDM_TransferHandleIRQ (PDM_Type base, pdm_handle_t handle)
	Tx interrupt handler. More...

Data Structure Documentation

struct pdm_channel_config_t

Data Fields
pdm_dc_remover_t	cutOffFreq
	DC remover cut off frequency.

pdm_df_output_gain_t	gain
	Decimation Filter Output Gain.

struct pdm_config_t

Data Fields
bool	enableDoze
	This module will enter disable/low leakage mode if DOZEN is active with ipg_doze is asserted.

uint8_t	fifoWatermark
	Watermark value for FIFO.

pdm_df_quality_mode_t	qualityMode
	Quality mode.

uint8_t	cicOverSampleRate
	CIC filter over sampling rate.

struct pdm_hwvad_config_t

Data Fields
uint8_t	channel
	Which channel uses voice activity detector.

uint8_t	initializeTime
	Number of frames or samples to initialize voice activity detector. More...

uint8_t	cicOverSampleRate
	CIC filter over sampling rate.

uint8_t	inputGain
	Voice activity detector input gain.

uint32_t	frameTime
	Voice activity frame time.

pdm_hwvad_hpf_config_t	cutOffFreq
	High pass filter cut off frequency.

bool	enableFrameEnergy
	If frame energy enabled, true means enable.

bool	enablePreFilter
	If pre-filter enabled.

Field Documentation

uint8_t pdm_hwvad_config_t::initializeTime

struct pdm_hwvad_noise_filter_t

Data Fields
bool	enableAutoNoiseFilter
	If noise fileter automatically activated, true means enable.

bool	enableNoiseMin
	If Noise minimum block enabled, true means enabled.

bool	enableNoiseDecimation
	If enable noise input decimation.

bool	enableNoiseDetectOR
	Enables a OR logic in the output of minimum noise estimator block.

uint32_t	noiseFilterAdjustment
	The adjustment value of the noise filter.

uint32_t	noiseGain
	Gain value for the noise energy or envelope estimated.

struct pdm_hwvad_zero_cross_detector_t

Data Fields
bool	enableAutoThreshold
	If ZCD auto-threshold enabled, true means enabled. More...

pdm_hwvad_zcd_result_t	zcdAnd
	Is ZCD result is AND'ed with energy-based detection, false means OR'ed.

uint32_t	threshold
	The adjustment value of the noise filter.

uint32_t	adjustmentThreshold
	Gain value for the noise energy or envelope estimated.

Field Documentation

bool pdm_hwvad_zero_cross_detector_t::enableAutoThreshold

struct pdm_transfer_t

Data Fields
volatile uint8_t *	data
	Data start address to transfer. More...

volatile size_t	dataSize
	Total Transfer bytes size. More...

Field Documentation

volatile uint8_t* pdm_transfer_t::data

volatile size_t pdm_transfer_t::dataSize

struct _pdm_handle

PDM handle.

Data Fields
uint32_t	state
	Transfer status.

pdm_transfer_callback_t	callback
	Callback function called at transfer event.

void *	userData
	Callback parameter passed to callback function.

pdm_transfer_t	pdmQueue [PDM_XFER_QUEUE_SIZE]
	Transfer queue storing queued transfer.

size_t	transferSize [PDM_XFER_QUEUE_SIZE]
	Data bytes need to transfer.

volatile uint8_t	queueUser
	Index for user to queue transfer.

volatile uint8_t	queueDriver
	Index for driver to get the transfer data and size.

uint32_t	format
	data format

uint8_t	watermark
	Watermark value.

uint8_t	startChannel
	end channel

uint8_t	channelNums
	Enabled channel number.

Enumeration Type Documentation

anonymous enum

Enumerator
kStatus_PDM_Busy	PDM is busy.
kStatus_PDM_CLK_LOW	PDM clock frequency low.
kStatus_PDM_FIFO_ERROR	PDM FIFO underrun or overflow.
kStatus_PDM_QueueFull	PDM FIFO underrun or overflow.
kStatus_PDM_Idle	PDM is idle.
kStatus_PDM_Output_ERROR	PDM is output error.
kStatus_PDM_ChannelConfig_Failed	PDM channel config failed.

enum _pdm_interrupt_enable

Enumerator
kPDM_ErrorInterruptEnable	PDM channel error interrupt enable.
kPDM_FIFOInterruptEnable	PDM channel FIFO interrupt.

enum _pdm_internal_status

Enumerator
kPDM_StatusDfBusyFlag	Decimation filter is busy processing data.
kPDM_StatusFIRFilterReady	FIR filter data is ready.
kPDM_StatusFrequencyLow	Mic app clock frequency not high enough.
kPDM_StatusCh0FifoDataAvaliable	channel 0 fifo data reached watermark level
kPDM_StatusCh1FifoDataAvaliable	channel 1 fifo data reached watermark level
kPDM_StatusCh2FifoDataAvaliable	channel 2 fifo data reached watermark level
kPDM_StatusCh3FifoDataAvaliable	channel 3 fifo data reached watermark level
kPDM_StatusCh4FifoDataAvaliable	channel 4 fifo data reached watermark level
kPDM_StatusCh5FifoDataAvaliable	channel 5 fifo data reached watermark level
kPDM_StatusCh6FifoDataAvaliable	channel 6 fifo data reached watermark level
kPDM_StatusCh7FifoDataAvaliable	channel 7 fifo data reached watermark level

enum _pdm_channel_enable_mask

Enumerator
kPDM_EnableChannel0	channgel 0 enable mask
kPDM_EnableChannel1	channgel 1 enable mask
kPDM_EnableChannel2	channgel 2 enable mask
kPDM_EnableChannel3	channgel 3 enable mask
kPDM_EnableChannel4	channgel 4 enable mask
kPDM_EnableChannel5	channgel 5 enable mask
kPDM_EnableChannel6	channgel 6 enable mask
kPDM_EnableChannel7	channgel 7 enable mask

enum _pdm_fifo_status

Enumerator
kPDM_FifoStatusUnderflowCh0	channel0 fifo status underflow
kPDM_FifoStatusUnderflowCh1	channel1 fifo status underflow
kPDM_FifoStatusUnderflowCh2	channel2 fifo status underflow
kPDM_FifoStatusUnderflowCh3	channel3 fifo status underflow
kPDM_FifoStatusUnderflowCh4	channel4 fifo status underflow
kPDM_FifoStatusUnderflowCh5	channel5 fifo status underflow
kPDM_FifoStatusUnderflowCh6	channel6 fifo status underflow
kPDM_FifoStatusUnderflowCh7	channel7 fifo status underflow
kPDM_FifoStatusOverflowCh0	channel0 fifo status overflow
kPDM_FifoStatusOverflowCh1	channel1 fifo status overflow
kPDM_FifoStatusOverflowCh2	channel2 fifo status overflow
kPDM_FifoStatusOverflowCh3	channel3 fifo status overflow
kPDM_FifoStatusOverflowCh4	channel4 fifo status overflow
kPDM_FifoStatusOverflowCh5	channel5 fifo status overflow
kPDM_FifoStatusOverflowCh6	channel6 fifo status overflow
kPDM_FifoStatusOverflowCh7	channel7 fifo status overflow

enum _pdm_range_status

Enumerator
kPDM_RangeStatusUnderFlowCh0	channel0 range status underflow
kPDM_RangeStatusUnderFlowCh1	channel1 range status underflow
kPDM_RangeStatusUnderFlowCh2	channel2 range status underflow
kPDM_RangeStatusUnderFlowCh3	channel3 range status underflow
kPDM_RangeStatusUnderFlowCh4	channel4 range status underflow
kPDM_RangeStatusUnderFlowCh5	channel5 range status underflow
kPDM_RangeStatusUnderFlowCh6	channel6 range status underflow
kPDM_RangeStatusUnderFlowCh7	channel7 range status underflow
kPDM_RangeStatusOverFlowCh0	channel0 range status overflow
kPDM_RangeStatusOverFlowCh1	channel1 range status overflow
kPDM_RangeStatusOverFlowCh2	channel2 range status overflow
kPDM_RangeStatusOverFlowCh3	channel3 range status overflow
kPDM_RangeStatusOverFlowCh4	channel4 range status overflow
kPDM_RangeStatusOverFlowCh5	channel5 range status overflow
kPDM_RangeStatusOverFlowCh6	channel6 range status overflow
kPDM_RangeStatusOverFlowCh7	channel7 range status overflow

enum pdm_dc_remover_t

Enumerator
kPDM_DcRemoverCutOff21Hz	DC remover cut off 21HZ.
kPDM_DcRemoverCutOff83Hz	DC remover cut off 83HZ.
kPDM_DcRemoverCutOff152Hz	DC remover cut off 152HZ.
kPDM_DcRemoverBypass	DC remover bypass.

enum pdm_df_quality_mode_t

Enumerator
kPDM_QualityModeMedium	quality mode memdium
kPDM_QualityModeHigh	quality mode high
kPDM_QualityModeLow	quality mode low
kPDM_QualityModeVeryLow0	quality mode very low0
kPDM_QualityModeVeryLow1	quality mode very low1
kPDM_QualityModeVeryLow2	quality mode very low2

enum _pdm_qulaity_mode_k_factor

Enumerator
kPDM_QualityModeHighKFactor	high quality mode K factor = 1 / 2
kPDM_QualityModeMediumKFactor	medium/very low0 quality mode K factor = 2 / 2
kPDM_QualityModeLowKFactor	low/very low1 quality mode K factor = 4 / 2
kPDM_QualityModeVeryLow2KFactor	very low2 quality mode K factor = 8 / 2

enum pdm_df_output_gain_t

Enumerator
kPDM_DfOutputGain0	Decimation filter output gain 0.
kPDM_DfOutputGain1	Decimation filter output gain 1.
kPDM_DfOutputGain2	Decimation filter output gain 2.
kPDM_DfOutputGain3	Decimation filter output gain 3.
kPDM_DfOutputGain4	Decimation filter output gain 4.
kPDM_DfOutputGain5	Decimation filter output gain 5.
kPDM_DfOutputGain6	Decimation filter output gain 6.
kPDM_DfOutputGain7	Decimation filter output gain 7.
kPDM_DfOutputGain8	Decimation filter output gain 8.
kPDM_DfOutputGain9	Decimation filter output gain 9.
kPDM_DfOutputGain10	Decimation filter output gain 10.
kPDM_DfOutputGain11	Decimation filter output gain 11.
kPDM_DfOutputGain12	Decimation filter output gain 12.
kPDM_DfOutputGain13	Decimation filter output gain 13.
kPDM_DfOutputGain14	Decimation filter output gain 14.
kPDM_DfOutputGain15	Decimation filter output gain 15.

enum _pdm_data_width

Enumerator
kPDM_DataWwidth24	PDM data width 24bit.
kPDM_DataWwidth32	PDM data width 32bit.

enum _pdm_hwvad_interrupt_enable

Enumerator
kPDM_HwvadErrorInterruptEnable	PDM channel HWVAD error interrupt enable.
kPDM_HwvadInterruptEnable	PDM channel HWVAD interrupt.

enum _pdm_hwvad_int_status

Enumerator
kPDM_HwvadStatusInputSaturation	HWVAD saturation condition.
kPDM_HwvadStatusVoiceDetectFlag	HWVAD voice detect interrupt triggered.

enum pdm_hwvad_hpf_config_t

Enumerator
kPDM_HwvadHpfBypassed	High-pass filter bypass.
kPDM_HwvadHpfCutOffFreq1750Hz	High-pass filter cut off frequency 1750HZ.
kPDM_HwvadHpfCutOffFreq215Hz	High-pass filter cut off frequency 215HZ.
kPDM_HwvadHpfCutOffFreq102Hz	High-pass filter cut off frequency 102HZ.

enum pdm_hwvad_filter_status_t

Enumerator
kPDM_HwvadInternalFilterNormalOperation	internal filter ready for normal operation
kPDM_HwvadInternalFilterInitial	interla filter are initial

enum pdm_hwvad_zcd_result_t

Enumerator
kPDM_HwvadResultOREnergyBasedDetection	zero cross detector result will be OR with energy based detection
kPDM_HwvadResultANDEnergyBasedDetection	zero cross detector result will be AND with energy based detection

Function Documentation

void PDM_Init	(	PDM_Type *	base,
		const pdm_config_t *	config
	)

Ungates the PDM clock, resets the module, and configures PDM with a configuration structure. The configuration structure can be custom filled or set with default values by PDM_GetDefaultConfig().

Note: This API should be called at the beginning of the application to use the PDM driver. Otherwise, accessing the PDM module can cause a hard fault because the clock is not enabled.

Parameters

base	PDM base pointer
config	PDM configuration structure.

void PDM_Deinit ( PDM_Type * base )

This API gates the PDM clock. The PDM module can't operate unless PDM_Init is called to enable the clock.

Parameters

base	PDM base pointer

static void PDM_Reset ( PDM_Type * base )

inlinestatic

Parameters

base	PDM base pointer

static void PDM_Enable	(	PDM_Type *	base,
		bool	enable
	)

inlinestatic

Parameters

base	PDM base pointer
enable	True means PDM interface is enabled, false means PDM interface is disabled.

static void PDM_EnableDoze	(	PDM_Type *	base,
		bool	enable
	)

inlinestatic

Parameters

base	PDM base pointer
enable	True means the module will enter Disable/Low Leakage mode when ipg_doze is asserted, false means the module will not enter Disable/Low Leakage mode when ipg_doze is asserted.

static void PDM_EnableDebugMode	(	PDM_Type *	base,
		bool	enable
	)

inlinestatic

The PDM interface cannot enter debug mode once in Disable/Low Leakage or Low Power mode.

Parameters

base	PDM base pointer
enable	True means PDM interface enter debug mode, false means PDM interface in normal mode.

static void PDM_EnableInDebugMode	(	PDM_Type *	base,
		bool	enable
	)

inlinestatic

Parameters

base	PDM base pointer
enable	True means PDM interface is enabled debug mode, false means PDM interface is disabled after after completing the current frame in debug mode.

static void PDM_EnterLowLeakageMode	(	PDM_Type *	base,
		bool	enable
	)

inlinestatic

Parameters

base	PDM base pointer
enable	True means PDM interface is in disable/low leakage mode, False means PDM interface is in normal mode.

static void PDM_EnableChannel	(	PDM_Type *	base,
		uint8_t	channel,
		bool	enable
	)

inlinestatic

Parameters

base	PDM base pointer
channel	PDM channel number need to enable or disable.
enable	True means enable PDM channel, false means disable.

void PDM_SetChannelConfig	(	PDM_Type *	base,
		uint32_t	channel,
		const pdm_channel_config_t *	config
	)

Parameters

base	PDM base pointer
config	PDM channel configurations.
channel	channel number. after completing the current frame in debug mode.

status_t PDM_SetSampleRateConfig	(	PDM_Type *	base,
		uint32_t	sourceClock_HZ,
		uint32_t	sampleRate_HZ
	)

Note: This function is depend on the configuration of the PDM and PDM channel, so the correct call sequence is
* PDM_Init(base, pdmConfig)

* PDM_SetChannelConfig(base, channel, &channelConfig)

* PDM_SetSampleRateConfig(base, source, sampleRate)

*

Parameters

base	PDM base pointer
sourceClock_HZ	PDM source clock frequency.
sampleRate_HZ	PDM sample rate.

status_t PDM_SetSampleRate	(	PDM_Type *	base,
		uint32_t	enableChannelMask,
		pdm_df_quality_mode_t	qualityMode,
		uint8_t	osr,
		uint32_t	clkDiv
	)

Deprecated:: Do not use this function. It has been superceded by PDM_SetSampleRateConfig

Parameters

base	PDM base pointer
enableChannelMask	PDM channel enable mask.
qualityMode	quality mode.
osr	cic oversample rate
clkDiv	clock divider

uint32_t PDM_GetInstance ( PDM_Type * base )

Parameters

base	PDM base pointer.

static uint32_t PDM_GetStatus ( PDM_Type * base )

inlinestatic

Use the Status Mask in _pdm_internal_status to get the status value needed

Parameters

base	PDM base pointer

Returns: PDM status flag value.

static uint32_t PDM_GetFifoStatus ( PDM_Type * base )

inlinestatic

Use the Status Mask in _pdm_fifo_status to get the status value needed

Parameters

base	PDM base pointer

Returns: FIFO status.

static uint32_t PDM_GetRangeStatus ( PDM_Type * base )

inlinestatic

Use the Status Mask in _pdm_range_status to get the status value needed

Parameters

base	PDM base pointer

Returns: output status.

static void PDM_ClearStatus	(	PDM_Type *	base,
		uint32_t	mask
	)

inlinestatic

Parameters

base	PDM base pointer
mask	State mask. It can be a combination of the status between kPDM_StatusFrequencyLow and kPDM_StatusCh7FifoDataAvaliable.

static void PDM_ClearFIFOStatus	(	PDM_Type *	base,
		uint32_t	mask
	)

inlinestatic

Parameters

base	PDM base pointer
mask	State mask.It can be a combination of the status in _pdm_fifo_status.

static void PDM_ClearRangeStatus	(	PDM_Type *	base,
		uint32_t	mask
	)

inlinestatic

Parameters

base	PDM base pointer
mask	State mask. It can be a combination of the status in _pdm_range_status.

void PDM_EnableInterrupts	(	PDM_Type *	base,
		uint32_t	mask
	)

Parameters

base	PDM base pointer
mask	interrupt source The parameter can be a combination of the following sources if defined. kPDM_ErrorInterruptEnable kPDM_FIFOInterruptEnable

static void PDM_DisableInterrupts	(	PDM_Type *	base,
		uint32_t	mask
	)

inlinestatic

Parameters

base	PDM base pointer
mask	interrupt source The parameter can be a combination of the following sources if defined. kPDM_ErrorInterruptEnable kPDM_FIFOInterruptEnable

static void PDM_EnableDMA	(	PDM_Type *	base,
		bool	enable
	)

inlinestatic

Parameters

base	PDM base pointer
enable	True means enable DMA, false means disable DMA.

static uint32_t PDM_GetDataRegisterAddress	(	PDM_Type *	base,
		uint32_t	channel
	)

inlinestatic

This API is used to provide a transfer address for the PDM DMA transfer configuration.

Parameters

base	PDM base pointer.
channel	Which data channel used.

Returns: data register address.

void PDM_ReadFifo	(	PDM_Type *	base,
		uint32_t	startChannel,
		uint32_t	channelNums,
		void *	buffer,
		size_t	size,
		uint32_t	dataWidth
	)

Note: : This function support 16 bit only for IP version that only supports 16bit.

Parameters

base	PDM base pointer.
startChannel	start channel number.
channelNums	total enabled channelnums.
buffer	received buffer address.
size	number of samples to read.
dataWidth	sample width.

static uint32_t PDM_ReadData	(	PDM_Type *	base,
		uint32_t	channel
	)

inlinestatic

Parameters

base	PDM base pointer.
channel	Data channel used.

Returns: Data in PDM FIFO.

void PDM_SetHwvadConfig	(	PDM_Type *	base,
		const pdm_hwvad_config_t *	config
	)

Parameters

base	PDM base pointer
config	Voice activity detector configure structure pointer .

static void PDM_ForceHwvadOutputDisable	(	PDM_Type *	base,
		bool	enable
	)

inlinestatic

Parameters

base	PDM base pointer
enable	true is output force disable, false is output not force.

static void PDM_ResetHwvad ( PDM_Type * base )

inlinestatic

It will reset VADNDATA register and will clean all internal buffers, should be called when the PDM isn't running.

Parameters

base	PDM base pointer

static void PDM_EnableHwvad	(	PDM_Type *	base,
		bool	enable
	)

inlinestatic

Should be called when the PDM isn't running.

Parameters

base	PDM base pointer.
enable	True means enable voice activity detector, false means disable.

static void PDM_EnableHwvadInterrupts	(	PDM_Type *	base,
		uint32_t	mask
	)

inlinestatic

Parameters

base	PDM base pointer
mask	interrupt source The parameter can be a combination of the following sources if defined. kPDM_HWVADErrorInterruptEnable kPDM_HWVADInterruptEnable

static void PDM_DisableHwvadInterrupts	(	PDM_Type *	base,
		uint32_t	mask
	)

inlinestatic

Parameters

base	PDM base pointer
mask	interrupt source The parameter can be a combination of the following sources if defined. kPDM_HWVADErrorInterruptEnable kPDM_HWVADInterruptEnable

static void PDM_ClearHwvadInterruptStatusFlags	(	PDM_Type *	base,
		uint32_t	mask
	)

inlinestatic

Parameters

base	PDM base pointer
mask	State mask,reference _pdm_hwvad_int_status.

static uint32_t PDM_GetHwvadInterruptStatusFlags ( PDM_Type * base )

inlinestatic

Parameters

base	PDM base pointer

Returns: status, reference _pdm_hwvad_int_status

static uint32_t PDM_GetHwvadInitialFlag ( PDM_Type * base )

inlinestatic

Parameters

base	PDM base pointer

Returns: initial flag.

static uint32_t PDM_GetHwvadVoiceDetectedFlag ( PDM_Type * base )

inlinestatic

NOte: this flag is auto cleared when voice gone.

Parameters

base	PDM base pointer

Returns: voice detected flag.

static void PDM_EnableHwvadSignalFilter	(	PDM_Type *	base,
		bool	enable
	)

inlinestatic

Parameters

base	PDM base pointer
enable	True means enable signal filter, false means disable.

void PDM_SetHwvadSignalFilterConfig	(	PDM_Type *	base,
		bool	enableMaxBlock,
		uint32_t	signalGain
	)

Parameters

base	PDM base pointer
enableMaxBlock	If signal maximum block enabled.
signalGain	Gain value for the signal energy.

void PDM_SetHwvadNoiseFilterConfig	(	PDM_Type *	base,
		const pdm_hwvad_noise_filter_t *	config
	)

Parameters

base	PDM base pointer
config	Voice activity detector noise filter configure structure pointer .

static void PDM_EnableHwvadZeroCrossDetector	(	PDM_Type *	base,
		bool	enable
	)

inlinestatic

Parameters

base	PDM base pointer
enable	True means enable zero cross detector, false means disable.

void PDM_SetHwvadZeroCrossDetectorConfig	(	PDM_Type *	base,
		const pdm_hwvad_zero_cross_detector_t *	config
	)

Parameters

base	PDM base pointer
config	Voice activity detector zero cross detector configure structure pointer .

static uint16_t PDM_GetNoiseData ( PDM_Type * base )

inlinestatic

Parameters

base	PDM base pointer.

Returns: Data in PDM noise data register.

static void PDM_SetHwvadInternalFilterStatus	(	PDM_Type *	base,
		pdm_hwvad_filter_status_t	status
	)

inlinestatic

Note: filter initial status should be asserted for two more cycles, then set it to normal operation.

Parameters

base	PDM base pointer.
status	internal filter status.

void PDM_SetHwvadInEnvelopeBasedMode	(	PDM_Type *	base,
		const pdm_hwvad_config_t *	hwvadConfig,
		const pdm_hwvad_noise_filter_t *	noiseConfig,
		const pdm_hwvad_zero_cross_detector_t *	zcdConfig,
		uint32_t	signalGain
	)

Recommand configurations,

 * static const pdm_hwvad_config_t hwvadConfig = {
 *   .channel           = 0,
 *   .initializeTime    = 10U,
 *   .cicOverSampleRate = 0U,
 *   .inputGain         = 0U,
 *   .frameTime         = 10U,
 *   .cutOffFreq        = kPDM_HwvadHpfBypassed,
 *   .enableFrameEnergy = false,
 *   .enablePreFilter   = true,
};
 * static const pdm_hwvad_noise_filter_t noiseFilterConfig = {
 *   .enableAutoNoiseFilter = false,
 *   .enableNoiseMin        = true,
 *   .enableNoiseDecimation = true,
 *   .noiseFilterAdjustment = 0U,
 *   .noiseGain             = 7U,
 *   .enableNoiseDetectOR   = true,
 * };
 * 

Parameters

base	PDM base pointer.
hwvadConfig	internal filter status.
noiseConfig	Voice activity detector noise filter configure structure pointer.
zcdConfig	Voice activity detector zero cross detector configure structure pointer .
signalGain	signal gain value.

void PDM_SetHwvadInEnergyBasedMode	(	PDM_Type *	base,
		const pdm_hwvad_config_t *	hwvadConfig,
		const pdm_hwvad_noise_filter_t *	noiseConfig,
		const pdm_hwvad_zero_cross_detector_t *	zcdConfig,
		uint32_t	signalGain
	)

Recommand configurations, code static const pdm_hwvad_config_t hwvadConfig = { .channel = 0, .initializeTime = 10U, .cicOverSampleRate = 0U, .inputGain = 0U, .frameTime = 10U, .cutOffFreq = kPDM_HwvadHpfBypassed, .enableFrameEnergy = true, .enablePreFilter = true, };

static const pdm_hwvad_noise_filter_t noiseFilterConfig = { .enableAutoNoiseFilter = true, .enableNoiseMin = false, .enableNoiseDecimation = false, .noiseFilterAdjustment = 0U, .noiseGain = 7U, .enableNoiseDetectOR = false, }; code param base PDM base pointer. param hwvadConfig internal filter status. param noiseConfig Voice activity detector noise filter configure structure pointer. param zcdConfig Voice activity detector zero cross detector configure structure pointer . param signalGain signal gain value, signal gain value should be properly according to application.

void PDM_TransferCreateHandle	(	PDM_Type *	base,
		pdm_handle_t *	handle,
		pdm_transfer_callback_t	callback,
		void *	userData
	)

This function initializes the handle for the PDM transactional APIs. Call this function once to get the handle initialized.

Parameters

base	PDM base pointer.
handle	PDM handle pointer.
callback	Pointer to the user callback function.
userData	User parameter passed to the callback function.

status_t PDM_TransferSetChannelConfig	(	PDM_Type *	base,
		pdm_handle_t *	handle,
		uint32_t	channel,
		const pdm_channel_config_t *	config,
		uint32_t	format
	)

Parameters

base	PDM base pointer.
handle	PDM handle pointer.
channel	PDM channel.
config	channel config.
format	data format, support data width configurations,_pdm_data_width.

Return values

kStatus_PDM_ChannelConfig_Failed or kStatus_Success.

status_t PDM_TransferReceiveNonBlocking	(	PDM_Type *	base,
		pdm_handle_t *	handle,
		pdm_transfer_t *	xfer
	)

Note: This API returns immediately after the transfer initiates. Call the PDM_RxGetTransferStatusIRQ to poll the transfer status and check whether the transfer is finished. If the return status is not kStatus_PDM_Busy, the transfer is finished.

Parameters

base	PDM base pointer
handle	Pointer to the pdm_handle_t structure which stores the transfer state.
xfer	Pointer to the pdm_transfer_t structure.

Return values

kStatus_Success	Successfully started the data receive.
kStatus_PDM_Busy	Previous receive still not finished.

void PDM_TransferAbortReceive	(	PDM_Type *	base,
		pdm_handle_t *	handle
	)

Note: This API can be called when an interrupt non-blocking transfer initiates to abort the transfer early.

Parameters

base	PDM base pointer
handle	Pointer to the pdm_handle_t structure which stores the transfer state.

void PDM_TransferHandleIRQ	(	PDM_Type *	base,
		pdm_handle_t *	handle
	)

Parameters

base	PDM base pointer.
handle	Pointer to the pdm_handle_t structure.

Overview

Typical use case

PDM receive using an interrupt method

PDM receive using a SDMA method

PDM receive using a EDMA method

PDM receive using a transactional method

Data Structures

Macros

Typedefs

Enumerations

Driver version

Initialization and deinitialization

Status

Interrupts

DMA Control

Bus Operations

Voice Activity Detector

Transactional

Data Structure Documentation

Data Fields

Data Fields

Data Fields

Field Documentation

Data Fields

Data Fields

Field Documentation

Data Fields

Field Documentation

Data Fields

Enumeration Type Documentation

Function Documentation