Specifications

V850E2/MN4 USB CDC (Communication Device Class) Driver
R01AN0010EJ0101 Rev.1.01 Page 18 of 117
Feb 01, 2012
4.1.3 Descriptor Settings
The descriptor settings that the sample driver makes are summarized in the tables below. The settings of the individual
descriptors are defined in the header file named “usbf850_desc.h.”
(1)
Device Descriptor
This descriptor is sent in response to a GET_DESCRIPTOR_device request.
Since the hardware automatically responds to the GET_DESCRIPTOR_device request, the settings are stored in the
USFA0DDn registers (n = 0 to 17) when the USB function controller is initialized.
Table 4.1 Device Descriptor Settings
Field
Size
(Bytes) Value Description
bLength 1 0x12 Size of the descriptor: 18 bytes
bDescriptorType 1 0x01 Type of the descriptor: Device
bcdUSB 2 0x0200 USB specification release number: USB 2.0
bDeviceClass 1 0x02 Class code: CDC
bDeviceSubClass 1 0x00 Subclass code: None
bDeviceProtocol 1 0x00 Protocol code: No unique protocol used
bMaxPacketSize0 1 0x40 Maximum packet size of Endpoint0: 64
idVendor 2 0x045B Vendor ID: Renesas Electronics
idProduct 2 0x0200 Product ID: V850E2/MN4
bcdDevice 2 0x0001 Device release number: First version
iManufacturer 1 0x01 Index of string descriptor describing the manufacturer: 1
iProduct 1 0x02 Index of string descriptor describing the product: 2
iSerialNumber 1 0x03
Index of string descriptor describing the serial number of the
device: 3
bNumConfigurations 1 0x01 Number of configurations: 1
(2)
Configuration 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.
Table 4.2 Configuration Descriptor Settings
Field
Size
(Bytes) Value Description
bLength 1 0x09 Size of the descriptor: 9 bytes
bDescriptorType 1 0x02 Type of the descriptor: Configuration
wTotalLength 2 0x0030
Total number of bytes of the configuration, interface, and
endpoint descriptors: 48 bytes
bNumInterfaces 1 0x02 Number of interfaces supported by this configuration: 2
bConfigurationValue 1 0x01 Identification number of this configuration: 1
iConfiguration 1 0x00 Index of the string descriptor describing this configuration: 0
bmAttributes 1 0x80
Characteristics of this configuration: Bus powered, no
remote wakeup
bMaxPower 1 0x1B Maximum consumption current of this configuration: 54 mA