EZ-USB TRM v1.9
Chapter 5. EZ-USB CPU
Page 5-13
The 8051 can ReNumerate
™ anytime. Once use for this capability might be to fine tune
an isochronous endpoint’s bandwidth requests by trying various descriptor values and
ReNumerating.
Tables 5-9 through 5-19 show the descriptor data built into the EZ-USB core. The tables
are presented in the order that the bytes are stored.
The Device Descriptor specifies a MaxPacketSize of 64 bytes for endpoint 0, contains
Cypress Semiconductor Vendor, Product and Release Number IDs, and uses no string
indices. Release Number IDs (XX and YY) are found in individual Cypress Semiconductor
data sheets. The EZ-USB core returns this information response to a “Get_Descriptor/
Device” host request.
5.10
Multiple ReNumerations
™
5.11
Default Descriptor
Table 5-9. USB Default Device Descriptor
Offset
Field
Description
Value
0
bLength
Length of this Descriptor = 18 bytes
12H
1
bDescriptorType
Descriptor Type = Device
01H
2
bcdUSB (L)
USB Specification Version 1.00 (L)
00H
3
bcdUSB (H)
USB Specification Version 1.00 (H)
01H
4
bDeviceClass
Device Class (FF is Vendor-Specific)
FFH
5
bDeviceSubClass
Device Sub-Class (FF is Vendor-Specific)
FFH
6
bDeviceProtocol
Device Protocol (FF is Vendor-Specific)
FFH
7
bMaxPacketSize0
Maximum Packet Size for EP0 = 64 bytes
40H
8
idVendor (L)
Vendor ID (L)
Cypress Semiconductor = 0547H
47H
9
idVendor (H)
Vendor ID (H)
05H
10
idProduct (L)
Product ID (L)
EZ-USB = 2131H
31H
11
idProduct (H)
Product ID (H)
21H
12
bcdDevice (L)
Device Release Number (BCD,L) (see individual data sheet)
21H
13
bcdDevice (H)
Device Release Number (BCD,H) (see individual data sheet)
YYH
14
iManufacturer
Manufacturer Index String = None
00H
15
iProduct
Product Index String = None
00H
16
iSerialNumber
Serial Number Index String = None
00H
17
bNumConfigurations
Number of Configurations in this Interface = 1
01H
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
