5.10 Multiple ReNumerations
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.
5.11 Default Descriptor
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.
Table 5-9. USB Default Device Descriptor
Offset
Field
bLength
Description
Length of this Descriptor = 18 bytes
Descriptor Type = Device
Value
12H
01H
00H
01H
FFH
FFH
FFH
40H
47H
05H
31H
21H
21H
YYH
00H
00H
00H
01H
0
1
2
3
4
5
6
7
8
9
bDescriptorType
bcdUSB (L)
USB Specification Version 1.00 (L)
USB Specification Version 1.00 (H)
Device Class (FF is Vendor-Specific)
Device Sub-Class (FF is Vendor-Specific)
Device Protocol (FF is Vendor-Specific)
Maximum Packet Size for EP0 = 64 bytes
Vendor ID (L) Cypress Semiconductor = 0547H
Vendor ID (H)
bcdUSB (H)
bDeviceClass
bDeviceSubClass
bDeviceProtocol
bMaxPacketSize0
idVendor (L)
idVendor (H)
10 idProduct (L)
Product ID (L) EZ-USB = 2131H
Product ID (H)
11
idProduct (H)
12 bcdDevice (L)
13 bcdDevice (H)
14 iManufacturer
15 iProduct
Device Release Number (BCD,L) (see individual data sheet)
Device Release Number (BCD,H) (see individual data sheet)
Manufacturer Index String = None
Product Index String = None
16 iSerialNumber
Serial Number Index String = None
17 bNumConfigurations Number of Configurations in this Interface = 1
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.
EZ-USB TRM v1.9
Chapter 5. EZ-USB CPU
Page 5-13
CYPRESS [ CYPRESS ]
