Datasheet

29. I2S - Inter-IC Sound Controller
29.1 Overview
The Inter-IC Sound Controller (I
2
S) provides bidirectional, synchronous and digital audio link with external
audio devices.
This controller is compliant with the Inter-IC Sound (I
2
S) bus specification. It supports TDM interface with
external multi-slot audio codecs. It also supports PDM interface with external MEMS microphones.
The I
2
S consists of two Clock Units and two Serializers, that can be enabled separately, to provide
Master, Slave, or controller modes, and operate as Receiver or Transmitter.
The pins associated with I
2
S peripheral are SDm, FSn, SCKn, and MCKn pins, where n=[0,1] denotes the
of clock unit and m=[0,1] is the Serializers instance.
FSn is referred to as Word Select in standard I
2
S mode operation and as Frame Sync in TDM mode.
Peripheral DMAC channels, separate for each Serializer, allow a continuous high bitrate data transfer
without processor intervention to the following:
• Audio codecs in Master, Slave, or Controller mode
• Stereo DAC or ADC through dedicated I
2
S serial interface
• Multi-slot or multiple stereo DACs or ADCs, using the TDM format
• Mono or stereo MEMS microphones, using the PDM interface
• 1-channel burst transfer with non-periodic Frame Sync
Each Serializer supports using either a single DMAC channel for all data channels, or two separate
DMAC channels for different data channels.
The I
2
S supports 8-bit and 16-bit compact stereo format. This helps in reducing the required DMA
bandwidth by transferring the left and right samples within the same data word.
Usually, an external audio codec or digital signal processor (DSP) requires a clock which is a multiple of
the sampling frequency fs (for example, 384×fs). The I
2
S peripheral in Master Mode and Controller mode
is capable of outputting an output clock ranging from 16×fs to 1024×fs on the Master Clock pin (MCKn).
29.2 Features
• Compliant with Inter-IC Sound (I
2
S) bus specification
• 2 independent Serializers configurable as receiver or as transmitter
• Supported data formats:
– 32-, 24-, 20-, 18-, 16-, and 8-bit mono or stereo format
– 16- and 8-bit compact stereo format, with left and right samples packed in the same word to
reduce data transfers
• Supported data frame formats:
– 2-channel I
2
S with Word Select
– 1- to 8-slot Time Division Multiplexed (TDM) with Frame Sync and individually enabled slots
– 1- or 2-channel Pulse Density Modulation (PDM) reception for MEMS microphones
– 1-channel burst transfer with non-periodic Frame Sync
• 2 independent Clock Units handling either the same clock or separate clocks for the Serializers:
SAM D21 Family
I2S - Inter-IC Sound Controller
© 2018 Microchip Technology Inc.
Datasheet Complete
DS40001882D-page 625