pdm_chan_cfg Struct Reference

Mapping/ordering of the PDM channels to logical PCM output channel. More...

#include <dmic.h>

Data Fields
uint8_t	req_num_chan
	Requested number of channels.
uint8_t	act_num_chan
	Actual number of channels that the driver could configure.
uint8_t	req_num_streams
	Requested number of streams for each channel.
uint8_t	act_num_streams
	Actual number of streams that the driver could configure.
Requested channel map
uint32_t	req_chan_map_lo
	Channels 0 to 7.
uint32_t	req_chan_map_hi
	Channels 8 to 15.
Actual channel map that the driver could configure
uint32_t	act_chan_map_lo
	Channels 0 to 7.
uint32_t	act_chan_map_hi
	Channels 8 to 15.

Detailed Description

Mapping/ordering of the PDM channels to logical PCM output channel.

Since each controller can have 2 audio channels (stereo), there can be a total of 8x2=16 channels. The actual number of channels shall be described in act_num_chan.

If 2 streams are enabled, the channel order will be the same for both streams.

Each channel is described as a 4-bit number, the least significant bit indicates LEFT/RIGHT selection of the PDM controller.

The most significant 3 bits indicate the PDM controller number:

• bits 0-3 are for channel 0, bit 0 indicates LEFT or RIGHT
• bits 4-7 are for channel 1, bit 4 indicates LEFT or RIGHT and so on.

CONSTRAINT: The LEFT and RIGHT channels of EACH PDM controller needs to be adjacent to each other.

Field Documentation

act_chan_map_hi

uint32_t pdm_chan_cfg::act_chan_map_hi

Channels 8 to 15.

act_chan_map_lo

uint32_t pdm_chan_cfg::act_chan_map_lo

Channels 0 to 7.

act_num_chan

uint8_t pdm_chan_cfg::act_num_chan

Actual number of channels that the driver could configure.

act_num_streams

uint8_t pdm_chan_cfg::act_num_streams

Actual number of streams that the driver could configure.

req_chan_map_hi

uint32_t pdm_chan_cfg::req_chan_map_hi

Channels 8 to 15.

req_chan_map_lo

uint32_t pdm_chan_cfg::req_chan_map_lo

Channels 0 to 7.

req_num_chan

uint8_t pdm_chan_cfg::req_num_chan

Requested number of channels.

req_num_streams

uint8_t pdm_chan_cfg::req_num_streams

Requested number of streams for each channel.

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

• zephyr/audio/dmic.h