Struct esp_idf_hal::i2s::config::TdmSlotConfig

pub struct TdmSlotConfig { /* private fields */ }

TDM mode slot configuration.

To create a slot configuration, use TdmSlotConfig::philips_slot_default, TdmSlotConfig::pcm_short_slot_default, TdmSlotConfig::pcm_long_slot_default, or TdmSlotConfig::msb_slot_default, then customize it as needed.

In TDM mode, WS (word select, sometimes called LRCLK or left/right clock) becomes a frame synchronization signal that signals the first slot of a frame. The two sides of the TDM link must agree on the number of channels, data bit width, and frame synchronization pattern; this cannot be determined by examining the signal itself.

The Philips default pulls the WS line low one BCK period before the first data bit of the first slot is sent and holds it low for 50% of the frame.

MSB (most-significant bit) mode is similar to Philips mode, except the WS line is pulled low at the same time the first data bit of the first slot is sent. It is held low for 50% of the frame.

PCM (pulse-code modulation) short mode pulls the WS line high one BCK period before the first data bit of the first slot is sent, keeps it high for one BCK, then pulls it low for the remainder of the frame. PCM long mode pulls the WS line high one BCK period before the first data bit of the first slot is sent, keeps it high until just before the last data bit of the first slot is sent, then pulls it low for the remainder of the frame.

Diagrams from ESP-IDF Programming Guide; rendered by Wavedrom.

Implementations

impl TdmSlotConfig

pub fn data_bit_width(self, data_bit_width: DataBitWidth) -> Self

Update the data bit width on this TDM slot configuration.

pub fn slot_bit_width(self, slot_bit_width: SlotBitWidth) -> Self

Update the slot bit width on this TDM slot configuration.

This is normally set to SlotBitWidth::Auto to match [data_bit_width][TdmSlotConfig::data_bit_width()].

pub fn slot_mask(self, slot_mask: TdmSlotMask) -> Self

Update the slot mask on this TDM slot configuration.

pub fn ws_width(self, ws_width: u32) -> Self

Update the word select signal width on this TDM slot configuration.

This sets the number of bits to keep the word select signal active at the start of each frame. If this is set to 0 (TDM_AUTO_WS_WIDTH), the word select signal will be kept active for half of the frame.

pub fn ws_polarity(self, ws_polarity: bool) -> Self

Update the word select signal polarity on this TDM slot configuration.

Setting this to true will make the word select (WS) signal active high at the start (PCM modes). Setting this to false will make the WS signal active low at the start (Philips and MSB modes).

pub fn bit_shift(self, bit_shift: bool) -> Self

Update the bit shift flag on this TDM slot configuration.

Setting this to true will activate the word select (WS) signal lone BCK period before the first data bit of the first slot is sent (Philips and PCM modes). Setting this to false will activate the WS signal at the same time the first data bit of the first slot is sent (MSB mode).

pub fn left_align(self, left_align: bool) -> Self

Update the left-alignment flag on this TDM slot configuration.

This only has an effect when [slot_bit_width][TdmSlotMask::slot_bit_width()] is greater than [data_bit_width][TdmSlotMask::data_bit_width()]. Setting this to true will left-align the data in the slot and fill the right-most bits (usually the least-significant bits) with zeros. Setting this to false will right-align the data in the slot and fill the left-most bits (usually the most-significant bits) with zeros.

pub fn big_endian(self, big_endian: bool) -> Self

Update the big-endian flag on this TDM slot configuration.

This affects the interpretation of the data when [data_bit_width][TdmSlotMask::data_bit_width()] is greater than 8. Setting this to true will interpret the data as big-endian. Setting this to false will interpret the data as little-endian (the default, and the native endian-ness of all ESP32 microcontrollers).

pub fn bit_order_lsb(self, bit_order_lsb: bool) -> Self

Update the LSB-first flag on this TDM slot configuration.

Setting this to true will transmit data LSB-first (no known modes do this). Setting this to false will transmit data MSB-first (the default for all known modes).

pub fn skip_mask(self, skip_mask: bool) -> Self

Update the skip mask flag on this TDM slot configuration.

Setting this to true will ignore [slot_mask][TdmSlotMask::slot_mask()] and transmit all slots. Setting this to false will respect the slot mask.

pub fn total_slots(self, total_slots: u32) -> Self

Update the total number of slots on this TDM slot configuration.

Setting this to 0 (TDM_AUTO_SLOT_NUM) will automatically set the total number of slots to the the number of active slots in [slot_mask][TdmSlotMask::slot_mask()].

pub fn philips_slot_default( bits_per_sample: DataBitWidth, slot_mask: TdmSlotMask, ) -> Self

Configure in Philips format with the active slots enabled by the specified mask.

pub fn msb_slot_default( bits_per_sample: DataBitWidth, slot_mask: TdmSlotMask, ) -> Self

Configure in MSB format with the active slots enabled by the specified mask.

pub fn pcm_short_slot_default( bits_per_sample: DataBitWidth, slot_mask: TdmSlotMask, ) -> Self

Configure in PCM (short) format with the active slots enabled by the specified mask.

pub fn pcm_long_slot_default( bits_per_sample: DataBitWidth, slot_mask: TdmSlotMask, ) -> Self

Configure in PCM (long) format with the active slots enabled by the specified mask.

Trait Implementations

impl Clone for TdmSlotConfig

fn clone(&self) -> TdmSlotConfig

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for TdmSlotConfig

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for TdmSlotConfig

fn eq(&self, other: &TdmSlotConfig) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for TdmSlotConfig

impl Eq for TdmSlotConfig

impl StructuralPartialEq for TdmSlotConfig