PDM - Pulse Density Modulation#

PDM_Ch1ClkPolarity_Typedef#

PDM_Ch1ClkPolarity_Typedef

Configure CH1 CLK Polarity.

PDM_Ch0ClkPolarity_Typedef#

PDM_Ch0ClkPolarity_Typedef

Configure CH0 CLK Polarity.

PDM_FifoValidWatermark_Typedef#

PDM_FifoValidWatermark_Typedef

Configure FIFO Data valid level water-mark.

PDM_DataFormat_TypeDef#

PDM_DataFormat_TypeDef

Configure PDM filter data output format.

PDM_NumberOfChannels_TypeDef#

PDM_NumberOfChannels_TypeDef

Configure number of PDM channels.

PDM_FilterOrder_TypeDef#

PDM_FilterOrder_TypeDef

Configure order of the PDM filter.

PDM_DeInit#

void PDM_DeInit (PDM_TypeDef * pdm)

De-initialize the PDM peripheral.

This function will stop the PDM filter and set PDM control registers to their reset values.

PDM_Init#

void PDM_Init (PDM_TypeDef * pdm, const PDM_Init_TypeDef * 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.

PDM_Reset#

void PDM_Reset (PDM_TypeDef * pdm)

Initialize PDM registers with reset values.

PDM_Clear#

void PDM_Clear (PDM_TypeDef * pdm)

Clear the PDM filter.

PDM_FifoFlush#

void PDM_FifoFlush (PDM_TypeDef * pdm)

Flush the PDM sample FIFO.

PDM_IntClear#

void PDM_IntClear (PDM_TypeDef * pdm, uint32_t flags)

Clear one or more pending PDM interrupts.

PDM_IntDisable#

void PDM_IntDisable (PDM_TypeDef * pdm, uint32_t flags)

Disable one or more PDM interrupts.

PDM_IntEnable#

void PDM_IntEnable (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 PDM_IntClear() prior to enabling the interrupt.

PDM_IntGet#

uint32_t PDM_IntGet (PDM_TypeDef * pdm)

Get pending PDM interrupt flags.

Note

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

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.

PDM_IntGetEnabled#

uint32_t PDM_IntGetEnabled (PDM_TypeDef * pdm)

Get enabled and pending PDM interrupt flags.

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

Note

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

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

PDM_IntSet#

void PDM_IntSet (PDM_TypeDef * pdm, uint32_t flags)

Set one or more pending PDM interrupts.

PDM_Rx#

uint32_t PDM_Rx (PDM_TypeDef * pdm)

Read one entry from the PDM 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.

Returns

• The entry read from the FIFO.

PDM_Start#

void PDM_Start (PDM_TypeDef * pdm)

Start the PDM operation (start the PDM filter).

PDM_StatusGet#

uint32_t PDM_StatusGet (PDM_TypeDef * pdm)

Get the PDM STATUS register.

Returns

• STATUS register value.

PDM_Stop#

void PDM_Stop (PDM_TypeDef * pdm)

Stop the PDM operation (stop the PDM filter).

PDM_INIT_DEFAULT#

#define PDM_INIT_DEFAULT

Default configuration for PDM.

Stereo Ch0/1, 16bit samples, 44,100 Hz sampling rate, 32 times oversampling (requires 1,411,209 Hz PDM clock).