BC352239A Datasheet, PDF (34/116 Pages) List of Unclassifed Manufacturers – BlueCore 3-Multimedia External

Description of Functional Blocks
6.8 Audio Interface
The audio interface circuit consists of a stereo audio CODEC, dual audio inputs and outputs, and a PCM, I²S or
SPDIF configurable interface. Figure 6.2 outlines the functional blocks of the interface. The CODEC supports
stereo playback and recording of audio signals at multiple sample rates with a resolution of 16-bit. The ADC and
the DAC of the CODEC each contain two independent channels. Any ADC or DAC channel can be run at its own
independent sample rate.
Memory
Management Unit
MMU Voice Port
Voice Port
MCU Register Interface
Registers
PCM
Digital Audio
Stereo
Audio
CODEC
Driver
PCM Interface
Digital Audio Interface
Left DAC
Right DAC
Left ADC
Right ADC
Figure 6.2: Audio Interface
The interface for the digital audio bus shares the same pins as the PCM CODEC Interface described in
Section 8.8.9. This means that each of the audio busses are mutually exclusive in their usage. The pin out for the
PCM interface with alternative pin descriptions can be seen in the device diagram shown in Figure 5.1 and Table
6.1 lists these alternative functions.
PCM Interface
SPDIF Interface
I²S Interface
PCM_OUT
PCM_IN
PCM_SYNC
PCM_CLK
SPDIF_OUT
SPDIF_IN
SD_OUT
SD_IN
WS
SCK
Table 6.1: Alternative Functions of the Digital Audio Bus Interface on the PCM Interface
6.8.1 Audio Input and Output
The audio input circuitry consists of a dual audio input that can be configured to be either single ended or fully
differential and programmed for either microphone or line input. It has a programmable gain stage for
optimisation of different microphones.
The audio output circuitry consists of a dual differential class A-B output stage.
6.8.2 Digital Audio Interface
The digital audio interface supports various digital audio bus standard, which include I²S, and the interfaces
contained within the IEC 60958 specification such as SPDIF and AES3⁽¹⁾.
Note:
(1) _{Subject to firmware support; contact CSR for current status.}
BC352239A-ds-001Pc
© Cambridge Silicon Radio Limited 2004
Production Information
Page 34 of 116