Overview

The MCUXpresso SDK provides Peripheral driver for the Digital Microphone (DMIC) module.
DMIC driver is created to help user to operate the DMIC module better. This driver can be used to performed basic and advance DMIC operations. Driver can be used to transfer data from DMIC to memory using DMA as well as in interrupt mode. DMIC, DMA transfer in pingpong mode is preferred as DMIC is a streaming device.

Function groups

Initialization and deinitialization

This function group implements DMIC initialization and deinitialization API. DMIC_Init() function Enables the clock to the DMIC register interface. DMIC_Dinit() function Disables the clock to the DMIC register interface.

Configuration

This function group implements DMIC configration API. DMIC_ConfigIO()function configures the use of PDM(Pulse Density moulation) pins. DMIC_SetOperationMode()function configures the mode of operation either in DMA or in interrupt. DMIC_ConfigChannel() function configures the various property of a DMIC channel. DMIC_Use2fs()function configures the Clock scaling used for PCM data output. DMIC_EnableChannnel() function enables a particualr DMIC channel. DMIC_FifoChannel() function configures FIFO settings for a DMIC channel.

DMIC Data and status

This function group implements the API to get data and status of DMIC FIFO. DMIC_FifoGetStatus() function gives the status of a DMIC FIFO. DMIC_ClearStatus() function clears the status of a DMIC FIFO. DMIC_FifoGetData() function gets data from a DMIC FIFO.

DMIC Interrupt Functions

DMIC_EnablebleIntCallback() enables the interrupt for the selected DMIC peripheral. DMIC_DisableIntCallback() disables the interrupt for the selected DMIC peripheral.

DMIC HWVAD Functions

This function group implements the API for HWVAD DMIC_SetGainNoiseEstHwvad() Sets the gain value for the noise estimator. DMIC_SetGainSignalEstHwvad() Sets the gain value for the signal estimator. DMIC_SetFilterCtrlHwvad() Sets the hwvad filter cutoff frequency parameter. DMIC_SetInputGainHwvad() Sets the input gain of hwvad. DMIC_CtrlClrIntrHwvad() Clears hwvad internal interrupt flag. DMIC_FilterResetHwvad() Resets hwvad filters. DMIC_GetNoiseEnvlpEst() Gets the value from output of the filter z7.

DMIC HWVAD Interrupt Functions

DMIC_HwvadEnableIntCallback() enables the hwvad interrupt for the selected DMIC peripheral. DMIC_HwvadDisableIntCallback() disables the hwvad interrupt for the selected DMIC peripheral.

Typical use case

DMIC DMA Configuration

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

DMIC use case