Data Fields
PDMCC26XX_Params Struct Reference

PDMCC26XX Parameters are used to with the PDMCC26XX_open() call. Default values for these parameters are set using PDMCC26XX_Params_init(). More...

#include <PDMCC26XX.h>

Collaboration diagram for PDMCC26XX_Params:
Collaboration graph

Data Fields

bool micPowerActiveHigh
bool applyCompression
uint8_t pdmBufferQueueDepth
uint16_t retBufSizeInBytes
const int32_t * decimationFilter
size_t decimationFilterStateSize
PDMCC26XX_Gain defaultFilterGain
PDMCC26XX_PcmSampleRate pcmSampleRate
uint32_t startupDelayWithClockInSamples
PDMCC26XX_CallbackFxn callbackFxn
PDMCC26XX_MallocFxn mallocFxn
PDMCC26XX_FreeFxn freeFxn
uintptr_t custom

Detailed Description

PDMCC26XX Parameters are used to with the PDMCC26XX_open() call. Default values for these parameters are set using PDMCC26XX_Params_init().

See also

Field Documentation

§ micPowerActiveHigh

bool PDMCC26XX_Params::micPowerActiveHigh

Set to TRUE if setting the GPIO high powers the microphone

§ applyCompression

bool PDMCC26XX_Params::applyCompression

Set to TRUE to apply compression. Setting it to FALSE allows user to apply own compression scheme.

§ pdmBufferQueueDepth

uint8_t PDMCC26XX_Params::pdmBufferQueueDepth

PDM buffer queue depth in number of blocks. We assume that we will be able to consume approximately one buffer per 2ms. This allows us to use the minium number of blocks (3) for the PDMCC26XX driver. If the application can not service the PDM task within the 2ms time window, increase this value to permit more latency in processing incoming PDM data at the cost of increased RAM useage.

§ retBufSizeInBytes

uint16_t PDMCC26XX_Params::retBufSizeInBytes

Size of returned buffers. It is not reccomended to make this value less than 64, the driver will not crash, but the sequence numbers may become unaligned with the data in the buffer.

§ decimationFilter

const int32_t* PDMCC26XX_Params::decimationFilter

Filter applied during PDM to PCM conversion. Will use default filter if NULL.

§ decimationFilterStateSize

size_t PDMCC26XX_Params::decimationFilterStateSize

Size of the decimation filter state information in bytes. Should be (6 + 2 * N) * sizeof(uint32_t) bytes long, where N is the number of filter stages in PDMCC26XX_Params.decimationFilter for the default signal processing chain. The decimation state will be allocated using the PDMCC26XX_Params.mallocFxn.

§ defaultFilterGain

PDMCC26XX_Gain PDMCC26XX_Params::defaultFilterGain

Gain of the signal chain before filtering. The decimation stage adds 12dB itself.

§ pcmSampleRate

PDMCC26XX_PcmSampleRate PDMCC26XX_Params::pcmSampleRate

Sample rate of the PCM output

§ startupDelayWithClockInSamples

uint32_t PDMCC26XX_Params::startupDelayWithClockInSamples

Some digital microphones have a startup delay. Set the number of samples to discard after powering the microphone starting to clock in data.

§ callbackFxn

PDMCC26XX_CallbackFxn PDMCC26XX_Params::callbackFxn

Callback function pointer

§ mallocFxn

PDMCC26XX_MallocFxn PDMCC26XX_Params::mallocFxn

Malloc function pointer

§ freeFxn

PDMCC26XX_FreeFxn PDMCC26XX_Params::freeFxn

Free function pointer

§ custom

uintptr_t PDMCC26XX_Params::custom

Custom argument used by driver implementation

The documentation for this struct was generated from the following file:
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