ORCA SOM/ORCA Hardware/Peripherals/Audio

History
Version	Issue Date	Notes
1.0.0	Feb 2021	First release

Contents

Peripheral AudioEdit

The Audio interface available on ORCA SoM is based on iMX8MPlus SoC which provides the following audio subsystems:

• Synchronous Audio Interface (SAI)
  • 6x I2S/SAI
• Sony/Philips Digital Interface (SPDIF)
• PDM microphone interface
• eARC

DescriptionEdit

The I2S module provides a synchronous audio interface (SAI) that supports full-duplex serial interfaces with frame synchronization such as I2S, AC97, TDM, and codec/DSP interfaces. It supports the following standards and features:

• Transmitter and receiver with independent bit clock and frame sync supporting 8 data lines
• Receiver with independent bit clock and frame sync supporting 8 data lines
• Each data line can support a maximum Frame size of 32 words
• Asynchronous 128 x 32-bit FIFO for each transmit and receive data line
• Supports packing of 8-bit and 16-bit data into each 32-bit FIFO word
• Supports combining multiple data line FIFOs into single data line FIFO
• Independent 32-bit timestamp counters and bit counters for monitoring transmit and receive progress

The Sony/Philips Digital Interface (SPDIF) audio block is a stereo transceiver that allows the processor to receive and transmit digital audio.

The PDM Microphone Interface (MICFIL) includes the following features:

• Decimation filters:
  • Fixed filtering characteristics for audio application.
  • 24-bit signed filter output.
  • Maximum dynamic range: 120dB.
  • Internal clock divider for a programmable PDM clock generation.
  • Full or partial set of channels operation with individual enable control.
  • Programmable decimation rate.
  • Programmable DC remover.
  • Range adjustement capability.
  • FIFOs with interrupt and DMA capability.
  • Each FIFO with 32 entries length.
• Hardware Voice Activity Detector (HWVAD).
  • Interrupt capability.
  • Zero-Crossing Detection (ZCD) option.

The enhanced audio return channel (eARC) provides an advanced audio stream through the HDMI interface.

The asyncronous sample rate converter (ASRC) is a digital module that converts audio from a source sample rate to a destination sample rate.

The primary features for the ASRC are as follows:

• 4 Contexts - groups of channels with an independent time base
• Fully independent and concurrent context control
• Simultaneous processing of up to 32 audio channels
• Programmable filter charachteristics for each context
• 32, 24, 20, and 16-bit fixed point audio sample support
• 32-bit floating point audio sample support
• 8kHz to 384 kHz sample rate
• 1/16 to 8x sample rate conversion ratio
• Software control of fine conversion ratio

Pin mappingEdit

The Pin mapping is described in the Pinout table section

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