PDM - Pulse Density Modulation#

sl_hal_pdm_ch_clock_polarity_t#

sl_hal_pdm_ch_clock_polarity_t

Configure channel clock polarity.

sl_hal_pdm_fifo_valid_watermark_t#

sl_hal_pdm_fifo_valid_watermark_t

Configure FIFO Data valid level water-mark.

sl_hal_pdm_data_format_t#

sl_hal_pdm_data_format_t

Configure PDM filter data output format.

sl_hal_pdm_number_of_channels_t#

sl_hal_pdm_number_of_channels_t

Configure number of PDM channels.

sl_hal_pdm_filter_order_t#

sl_hal_pdm_filter_order_t

Configure order of the PDM filter.

ch0ch1_stereo_enable#

bool sl_hal_pdm_init_t::ch0ch1_stereo_enable

Enable stereo mode for channel pair CH0 and CH1.

filter_order#

sl_hal_pdm_filter_order_t sl_hal_pdm_init_t::filter_order

PDM filter order.

number_channels#

sl_hal_pdm_number_of_channels_t sl_hal_pdm_init_t::number_channels

Number of PDM channels.

data_format#

sl_hal_pdm_data_format_t sl_hal_pdm_init_t::data_format

PDM filter data output format.

fifo_valid_watermark#

sl_hal_pdm_fifo_valid_watermark_t sl_hal_pdm_init_t::fifo_valid_watermark

FIFO Data valid level water-mark.

ch0_clock_polarity#

sl_hal_pdm_ch_clock_polarity_t sl_hal_pdm_init_t::ch0_clock_polarity

Ch 0 clock polarity.

ch1_clock_polarity#

sl_hal_pdm_ch_clock_polarity_t sl_hal_pdm_init_t::ch1_clock_polarity

Ch 1 clock polarity.

gain#

uint32_t sl_hal_pdm_init_t::gain

PDM gain.

down_sampling_rate#

uint32_t sl_hal_pdm_init_t::down_sampling_rate

PDM down sampling rate.

clk_prescaler#

uint32_t sl_hal_pdm_init_t::clk_prescaler

PDM clock prescaler, resulting PDM clock is input clock / (prescaler + 1).

sl_hal_pdm_init#

void sl_hal_pdm_init (PDM_TypeDef * pdm, const sl_hal_pdm_init_t * init)

Initialize the PDM peripheral.

This function will configure basic settings in PDM according to values in the initialization data structure. Notice that enabling of PDM clock, setup of PDM pins and setup of PRS is not covered by this function.

sl_hal_pdm_reset#

void sl_hal_pdm_reset (PDM_TypeDef * pdm)

Initialize PDM registers with reset values.

sl_hal_pdm_wait_sync#

void sl_hal_pdm_wait_sync (PDM_TypeDef * pdm)

Waits for the PDM to complete all synchronization of register changes and commands.

sl_hal_pdm_wait_ready#

void sl_hal_pdm_wait_ready (PDM_TypeDef * pdm)

Waits for the PDM to complete disabling procedure.

Note

• This function is only needed if the PDM peripheral supports disabling bit in the EN register. If the PDM peripheral doesn't support, this function will do nothing.

sl_hal_pdm_enable#

void sl_hal_pdm_enable (PDM_TypeDef * pdm)

Enable the PDM peripheral.

sl_hal_pdm_disable#

void sl_hal_pdm_disable (PDM_TypeDef * pdm)

Disable the PDM peripheral.

sl_hal_pdm_clear#

void sl_hal_pdm_clear (PDM_TypeDef * pdm)

Clear the PDM filter.

sl_hal_pdm_fifo_flush#

void sl_hal_pdm_fifo_flush (PDM_TypeDef * pdm)

Flush the PDM sample FIFO.

sl_hal_pdm_start#

void sl_hal_pdm_start (PDM_TypeDef * pdm)

Start the PDM operation (start the PDM filter).

sl_hal_pdm_stop#

void sl_hal_pdm_stop (PDM_TypeDef * pdm)

Stop the PDM operation (stop the PDM filter).

sl_hal_pdm_rx#

uint32_t sl_hal_pdm_rx (PDM_TypeDef * pdm)

Read one entry from the PDM FIFO.

Returns

• The entry read from the FIFO.

Note

• This function will wait until a sample is available in the FIFO. Depending on PDM configuration, a FIFO entry can consist of one or two samples.

sl_hal_pdm_get_status#

uint32_t sl_hal_pdm_get_status (PDM_TypeDef * pdm)

Get the PDM STATUS register.

Returns

• STATUS register value.

sl_hal_pdm_clear_interrupts#

void sl_hal_pdm_clear_interrupts (PDM_TypeDef * pdm, uint32_t flags)

Clear one or more pending PDM interrupts.

sl_hal_pdm_set_interrupts#

void sl_hal_pdm_set_interrupts (PDM_TypeDef * pdm, uint32_t flags)

Set one or more pending PDM interrupts.

sl_hal_pdm_enable_interrupts#

void sl_hal_pdm_enable_interrupts (PDM_TypeDef * pdm, uint32_t flags)

Enable one or more PDM interrupts.

Note

• Depending on the use, a pending interrupt may already be set prior to enabling the interrupt. To ignore a pending interrupt, consider using sl_hal_pdm_clear_interrupts() prior to enabling the interrupt.

sl_hal_pdm_disable_interrupts#

void sl_hal_pdm_disable_interrupts (PDM_TypeDef * pdm, uint32_t flags)

Disable one or more PDM interrupts.

sl_hal_pdm_get_pending_interrupts#

uint32_t sl_hal_pdm_get_pending_interrupts (PDM_TypeDef * pdm)

Get pending PDM interrupt flags.

Returns

• PDM interrupt sources pending. Returns one or more valid interrupt flags for PDM module. The flags are PDM_IF_DV, PDM_IF_DVL, PDM_IF_OF and PDM_IF_UF.

Note

• Event bits are not cleared by the use of this function.

sl_hal_pdm_get_enabled_pending_interrupts#

uint32_t sl_hal_pdm_get_enabled_pending_interrupts (PDM_TypeDef * pdm)

Get enabled and pending PDM interrupt flags.

Useful for handling more interrupt sources in the same interrupt handler.

Returns

• Pending and enabled PDM interrupt sources Return value is the bitwise AND of

  • the enabled interrupt sources in PDM_IEN and

  • the pending interrupt flags PDM_IF

Note

• Interrupt flags are not cleared by the use of this function.