Cypress EZ-USB HX2LP - Manual (Page 10)

CY7C656xx PRELIMINARY
Document #: 38-08037 Rev. *D Page 10 of 23
8.0 Default Descriptors
8.1 Device Descriptor
The standard device descriptor for CY7C656xx is based on the VID, PID, and DID found in the SPI EEPROM. This VID/PID/DID
in the EEPROM will overwrite the default VID/PID/DID. If no EEPROM is used, the CY7C656xx will enumerate with the default
descriptor values as shown below.
8.2 Configuration Descriptor
8.3 Interface Descriptor
Byte Full Speed High Speed Field Name Description
0 0x12 0x12 bLength 18 Bytes
1 0x01 0x01 bDescriptorType DEVICE_DESCRIPTOR
2,3 0x0110 0x0200 bcdUSB USB specification 2.0 in HS (1.1 if forced FS)
4 0x09 0x09 bDeviceClass HUB
5 0x00 0x00 bDeviceSubClass None
6 0x00 0x01
[4]
/ 0x02
[5]
bDeviceProtocol None
7 0x40 0x40 bMaxPacketSize0 64 bytes
8,9 0x04B4 0xx04B4 wIdVendor VID (overwritten by what is defined in EEPROM)
10,11 0x6560 0x6560 wIdProduct PID (overwritten by what is defined in EEPROM)
12, 13 0x0910
0x0810 0x0910
0x0810 wbcdDevice DID (overwritten by what is defined in EEPROM)
14 0x00 0x00 iManufacturer No manufacturer string supported
15 0x00 0x00 iProduct No product string supported
16 0x00 0x00 iSerialNumber No serial string supported
17 0x01 0x01 bNumConfigurations One configuration supported
Byte Full Speed High Speed Field Name Description
0 0x09 0x09 bLength 9 Bytes
1 0x02 [7] / 0x07 [8] 0x02 [7] / 0x07 [8] bDescriptorType CONFIG_DESCRIPTOR
2 0x0019
0x0029 0x0019
[4]
0x0029
[5]
wTotalLength Length of all other descriptors
4 0x01 0x01 bNumInterfaces 1
5 0x01 0x01 bConfigurationValue The configuration to be used
6 0x00 0x00 iConfiguration
7 0xA0
0xE0 0xA0
0xE0 bmAttributes Value depends on pin 45 - SELFPWR signal
SELFPWR = 0 yields 0xA0 and =1 yields 0xE0
8 0x28 0x57
[6]
bMaxPower
Byte Full Speed High Speed Field Name Description
0 0x09 0x09 bLength 9 Bytes
1 0x04 0x04 bDescriptorType INTERFACE_DESCRIPTOR
2 0x00 0x00 bInterfaceNumber
3 0x00 0x00 bAlternateSetting
4 0x01 0x01 bNumEndpoints
5 0x09 0x09 bInterfaceClass
6 0x00 0x00 bInterfaceSubClass
7 0x00
[4]
/ 0x01
[5]
0x00
[4]
/ 0x01
[5]
bInterfaceProtocol
8 0x00 0x00 iInterface
Notes:
4. If configured as single-TT hub.
5. If configured as multi-TT hub and other speed.
6. This value is configured through the External EEPROM.
7. Configured speed descriptor
8. Other speed descriptor