Cirrus Logic CRD49530-USB - Manual (Page 30)

4-5 Copyright 2008 Cirrus Logic DS705RD3
Changing Audio Input Source
CRD49530-USB User’s Manual
4.3.2 Analog Audio Input
To deliver data to the DSP via 6ch ADC, drag the Audio In block to the work space and select “Analog” as
the Input Source. Double click the Audio In block to see the signal flow. The Device properties of the
Analog element lets you select the sampling frequency of the ADC on the CS42448 CODEC. The Master/
Slave property must always be set to Master to indicate that the ADC will master SCLK and LRCLK as
described in
Section 1.3.10 “Audio Clocking” on page 1-6 . The Audio In module with Analog as the input
source is illustrated in Figure 4-6 .
Figure 4-6. CRD49530 Analog Properties
This S/PDIF and Analog dialog allows the user to set the following parameters:
• Input and Output Sampling Frequency Range - Select the Fs range where
- 1FS = 32 kHz, 44.1 kHz, or 48 kHz
- 2Fs = 64 kHz, 88.2 kHz, 96 kHz
- 4FS= 128 kHz, 176.4 kHz, 192 kHz
• Master/Slave settings for the SCLK & LRCLK pins on the CS8416. Set to Master when using S/PDIF
input.
• SPDIF Mux: RX0 - RX3, and ‘NONE’. Choosing ‘NONE’ forces the CS8416 to pass the DSP clock that
comes in on the OMCK pin to MUXED_MCLK (RMCK). Use this setting when using the ADC.
• Analog Only - Enable microphone input.
4.3.3 USB (I
2
S) Audio Input
This feature is used for debugging and development purposes via the usb_play utility.