ASAHI KASEI
[AK4571]
2.8.2.
デスクリプタ概要
デバイスをホストに接続すると、ホストは、デバイスに対して固有のアドレスを割り当てた後、デフォルトパイプを通してデバイスの情報
（デスクリプタ）をリードします。デスクリプタは、(1)Device Descriptor, (2) Configuration Descriptor, (3) Interface Descrip tor (4) Endpoint
Descriptor, (5) String Descriptorよりｌ構成されます。
AK4571では、1つのConfiguration, 4つのInterfaceを持つデバイスとして定義されます。
また、Interface 0用に１つ、Interface 1(A/D用)に１つ、Interface 2（D/A用）に1つ、Interface 3(HID用)に1つのEndpoint(EP)を持ちます。
Device
Device
Descriptor
Configuration
Configuration
Descriptor
Interface
Interface 0
Interface 1
Interface 2
Interface 3
Standard AS Interface
Standard Audio Control
Interface Descriptor
Standard AS Interface
Descriptor Alt. Setting 0
Standard AS Interface
Descriptor Alt. Setting 0
Descriptor Alt. Setting 0
Class-Specific Audio Control
Interface Descriptor
Standard AS Interface
Descriptor Alt. Setting 1
Standard AS Interface
Descriptor Alt. Setting 1,2
HID Descriptor
Input Terminal
Descriptor
Class-Specific Audio Streaming
Interface Descriptor
Class-Specific Audio Streaming
Interface Descriptor
Standard HID Interrupt
Endpoint Descriptor
Output Terminal
Descriptor
Class-Specific AS Format Type
Descriptor
Class-Specific AS Format Type
Descriptor
IN Endpoint
(interrupt)
Feature Unit
Descriptor(Mute,Volume,AGC)
Standard AS Isochronous
Endpoint Descriptor
Standard AS Isochronous
Endpoint Descriptor
Mixer Unit Descriptor
Selector Unit Descriptor
Class-Specific AS Isochronous
Endpoint Descriptor
Class-Specific AS Isochronous
Endpoint Descriptor
IN Endpoint
(Isochronous)
OUT Endpoint
(Isochronous)
Figure 13 Descriptor Hierarchy
MS0153-J-02
2003/3
- 23 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
