Specifications

V850E2/MN4 USB CDC (Communication Device Class) Driver

R01AN0010EJ0101 Rev.1.01 Page 19 of 117

Feb 01, 2012

(3)

Interface Descriptor

This descriptor is sent in response to a GET_DESCRIPTOR_configuration request.

Since the hardware automatically responds to the GET_DESCRIPTOR_configuration request, the settings are stored in

the USFA0CIEn registers (n = 0 to 255) when the USB function controller is initialized.

Since the sample driver uses two endpoints, two endpoint descriptors are set up.

Table 4.3 Interface 0 Interface Descriptor Settings

Field

Size

(Bytes) Value Description

bLength 1 0x09 Size of the descriptor: 9 bytes

bDescriptorType 1 0x04 Type of the descriptor: Interface

bInterfaceNumber 1 0x00 Identification number of this interface: 0

bAlternateSetting 1 0x00

Presence or absence of alternate setting for this interface:

Absence

bNumEndpoints 1 0x01 Number of endpoints used by this interface: 1

bInterfaceClass 1 0x02 Class code: Communication interface class

bInterfaceSubClass 1 0x02 Subclass code: Abstract Control Model

bInterfaceProtocol 1 0x00 Protocol code: No unique protocol used

iInterface 1 0x00 Index of the string descriptor describing this interface: 0

Table 4.4 Interface 1 Interface Descriptor Settings