Cirrus Logic CDB42L52 - Manual (Page 4)

4 DS680DB1
CDB42L52
1.5 CS8406 Digital Audio Transmitter
A complete description of the CS8406 transmitter ( Figure 4 on page 17 ) and a discussion of the digital audio
interface can be found in the CS8406 data sheet.
The CS8406 converts the PCM data generated by the CS42L52 to the standard S/PDIF data stream and
routes this signal to the optical and RCA connectors on the CDB42L52.
Selections are made by using the “Board Configuration” tab of the Cirrus FlexGUI software. Section 2. “Soft-
ware Mode Control” on page 6 provide configuration details.
1.6 CS8416 Digital Audio Receiver
A complete description of the CS8416 receiver ( Figure 4 on page 17 ) and a discussion of the digital audio
interface can be found in the CS8416 data sheet.
The CS8416 converts the input S/PDIF data stream from the optical or RCA connector into PCM data that
is input to the CS42L52.
Selections are made by using the “Board Configuration” tab of the Cirrus FlexGUI software. Section 2. “Soft-
ware Mode Control” on page 6 provides configuration details.
1.7 Oscillator
The socketed on-board oscillator can be selected as the system master clock source by using the selections
on the “Board Configuration” tab of the Cirrus FlexGUI.
Section 2. “Software Mode Control” on page 6 pro-
vides configuration details.
The oscillator is mounted in pin sockets, allowing easy removal or replacement. The device footprint on the
board will accommodate full- or half-can-sized oscillators.
1.8 I/O Stake Headers
The evaluation board has been designed to allow interfacing with external systems via a serial port header
(reference designation J8) and a control port header (reference designation J109). The serial port header
provides access to the serial audio signals required to interface with a DSP (
Figure 10 on page 19 ). Selec-
tions are made by using the “Board Configuration” tab of the Cirrus FlexGUI software. Section 2. “Software
Mode Control” on page 6 provides configuration details.
The control port header provides bidirectional access to the I²C control port signals by simply removing all
the shunt jumpers from the “USB” position. The user may then connect a ribbon cable connector to the “Ext
Sys Connect” pins for external control of board functions. A single row of “GND” pins are provided to main-
tain signal ground integrity. Two unpopulated pull-up resistors are also available should the user choose to
use the CDB42L52 logic supply (VL) externally.