Serial Port Complete - Latest Microcontroller projects

Using Generic USB Controllers

Device

Configuration

Interface

(CDC Communication)

Interface

(CDC Data)

Header

Functional

Abstract Control

Model

Functional

Union

Functional

Call Management

Functional

Endpoint

(Interrupt IN)

Endpoint

(Bulk OUT )

Endpoint

(Bulk IN)

USB standard

descriptor type

Class-specific

descriptor type

Interface

(HID)

Endpoint

(Interrupt IN)

HID

Endpoint

(Interrupt OUT )

Interface Association

Figure 16-2: A composite device that contains a CDC function and a HID function
can use an interface association descriptor to specify the CDC interfaces.