TechNexion EDM1-IMX6PLUS, Руководство по оборудованию

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EDM1-IMX6PLUS HARDWARE MANUAL
– VER 1.00 – NOV 16 2016
Page 42 of 83
3.5. Audio Interface
The EDM1-IMX6PLUS incorporates two I
2
S / AUDMUX signals, one S/P DIF interface and can as well
provide surround audio over the HDMI data signals.
The AUDMUX provides flexible, programmable routing of the serial interfaces (SSI1 or SSI2) to and from
off-chip devices. The AUDMUX routes audio data (and even splices together multiple time-multiplexed
audio streams) but does not decode or process audio data itself. The AUDMUX is controlled by the ARM
but can route data even when the ARM is in a low-power mode.
The ESAI (Enhanced Serial Audio Interface) provides a full-duplex serial port for serial communication
with a variety of serial devices, including industry-standard codecs, SPDIF transceivers, and other
processors. The ESAI consists of independent transmitter and receiver sections, each section with its
own clock generator. The ESAI is connected to the IOMUX and to the ESAI_BIFIFO module.
The ESAI_BIFIFO (ESAI Bus Interface and FIFO) is the interface between the ESAI module and the
shared peripheral bus. It contains the FIFOs used to buffer data to and from the ESAI, as well as
providing the data word alignment and padding necessary to match the 24-bit data bus of the ESAI to the
32-bit data bus of the shared peripheral bus.
The SPDIF (Sony/Philips Digital Interface) audio module is a stereo transceiver that allows the processor
to receive and transmit digital audio over it. The SPDIF receiver section includes a frequency
measurement block that allows the precise measurement of incoming sampling frequency. A recovered
clock is provided by the SPDIF receiver section and may be used to drive both internal and external
components in the system. The SPDIF is connected to the shared peripheral bus.
The ASRC (Asynchronous Sample Rate Converter) converts the sampling rate of a signal associated to
an input clock into a signal associated to a different output clock. The ASRC supports concurrent sample
rate conversions of up to 10 channels of over 120dB THD+N. The sample rate conversion of each
channel is associated to a pair of incoming and outgoing sampling rates. The ASRC supports up to three
sampling rate pairs. The ASRC is connected to the shared peripheral bus.
Key features of the audio signal block include:

Full 6-wire SSI interfaces for asynchronous receive and transmit

Configurable 4-wire (synchronous) or 6-wire (asynchronous) peripheral interfaces

Independent Tx/Rx frame sync and clock direction selection for host or peripheral

Each host interface's capability to connect to any other host or peripheral interface in a point-to-
point or point-to-multipoint (network mode)

Transmit and receive data switching to support external network mode