PCM2704,PCM2705

PCM2706,PCM2707

SLES081A − JUNE 2003 – REVISED MAY 2004

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17

Device Configuration

Figure 21 illustrates the USB audio function topology. The PCM2704/5/6/7 has three interfaces. Each interface is

enabled by some alternative settings.

Analog Out

Default

Endpoint

Endpoint #2

(IF #1)

Audio Streaming

Interface

Endpoint #0

Endpoint #5

(IF #2)

HID Interface

IT

TID1

FU

UID3

OT

TID2

Standard Audio Control Interface (IF #0)

PCM2704/5/6/7

Figure 21. USB Audio Function Topology

Interface #0 (Default/Control Interface)

Interface #0 is the control interface. Setting #0 is the only possible setting for interface #0. Setting #0 describes the

standard audio control interface. Audio control interface consists of a terminal. The PCM2704/5/6/7 has three

terminals as follows.

Input terminal #1 is defined as a USB stream (terminal type 0x0101). Input terminal #1 can accept two-channel audio

streams constructed of left and right channels. Output terminal #2 is defined as a speaker (terminal type 0x0301).

Feature unit #3 supports the following sound control features.

The built-in digital volume controller can be manipulated by an audio-class-specific request from 0 dB to –64 dB in

the volume level reaches the requested value. Each channel can be set to a separate value. The master volume

control is not supported. A request to the master volume is stalled and ignored. The built-in digital mute controller

can be manipulated by an audio-class-specific request. A master mute control request is acceptable. A mute control

outputs (PCM2706/7).