Cirrus Logic CK4970x4 - Manual (Page 15)

CK49x System Description
CK49x User’s Manual
DS898CK7 Copyright 2012 Cirrus Logic, Inc 1-8
The output buffer currently enabled is indicated by the LEDs D18 - D23.
1.3.9 DAI1 Audio Input Source Multiplexer
The audio input source multiplexer has the following characteristics:
• Source 0 [shunt removed]: HDMI RX I2S Audio
• Source 1 [shunt installed]: I
2 S Audio (ASIO I 2 S Board)
• Reference Designators: U15, U28
This multiplexer is controlled by pins 1-2 of header P4, and is used to select which audio source feeds the
CS495xxx/CS497xxx DAI1 pins when the ASIO I
2 S Board is installed. When the on-board sources (HDMI
RX) are being used, the ASIO audio data cannot be processed. Likewise, when the ASIO audio data
source (ASIO I
2 S Board) is selected, the on-board audio inputs are disabled.
1.3.10 DAI2 Audio Input Source Multiplexer
The audio input source multiplexer has the following characteristics:
• Source 0: CS42528 Audio (ADC or S/PDIF)
• Source 1: Bi-Phase Encoded S/PDIF Signal
• Reference Designator: U23
This multiplexer is controlled by GPO1 of the CS42528 (U5), and is used to select which audio sources
feed the CS495xxx/CS497xxx DAI2 pins. When the DSD audio from HDMI RX is being used, the
CS42528 data cannot be processed. Likewise, when the CS42528 audio is selected, the HDMI RX DSD
audio is disabled.
1.3.11 CS495xxx/CS497xxx Audio DSP
The audio DSP (U1 on DSP Daughtercard) is a dual-core processor designed specifically for audio
applications. The CK49x allows a designer to evaluate the CS495xxx/CS497xxx DSPs in many different
modes of multi-channel input and output. The 128-pin footprint on this board is compatible with any
CS495xxx/CS497xxx chip that uses the LQFP128 package.
Audio input data to the DSP can come from any of the following sources:
• CS42528 Line-Level Analog In
• CS42528 Microphone Analog In
• CS42528 Digital S/PDIF In
• HDMI RX
• I
2 S Through ASIO I 2 S Board (feature not currently supported)
Audio output data from the DSP can be sent to the following destinations:
• CS42528 Line-Level Analog Output
• CS42528 Headphone Analog Output
• CS42528 Digital S/PDIF Out
• HDMI TX
• I
2 S Through Header P16