EZ-USB Datasheet, PDF (90/334 Pages) Cypress Semiconductor – The EZ-USB USB Integrated Circuit

Table 5-12. USB Default Interface 0, Alternate Setting 1 Descriptor
Offset
Field
0 bLength
1 bDescriptorType
2 bInterfaceNumber
3 bAlternateSetting
4 bNumEndpoints
5 bInterfaceClass
6 bInterfaceSubClass
7 bInterfaceProtocol
8 iInterface
Description
Value
Length of the Interface Descriptor
09H
Descriptor Type = Interface
04H
Zero-based Index of this Interface = 0
00H
Alternate Setting Value = 1
01H
Number of Endpoints in this Interface (Not Counting EPO) = 13 0DH
Interface Class = Vendor Specific
FFH
Interface Sub-class = Vendor Specific
FFH
Interface Protocol = Vendor Specific
FFH
Index to String Descriptor for this Interface = None
00H
Interface 0, alternate setting 1 has thirteen endpoints, whose individual descriptors follow
the interface descriptor. The alternate settings have no string indices.
Table 5-13. USB Default Interface 0, Alternate Setting 1, Interrupt Endpoint Descriptor
Offset
Field
Description
0 bLength
Length of this Endpoint Descriptor
1 bDescriptorType
Descriptor Type = Endpoint
2 bEndpointAddress Endpoint Direction (1 is in) and Address = IN1
3 bmAttributes
XFR Type = INT
4 wMaxPacketSize (L) Maximum Packet Size = 16 Bytes
5 wMaxPacketSize (H) Maximum Packet Size - High
6 bInterval
Polling Interval in Milliseconds = 10 ms
Value
07H
05H
81H
03H
10H
00H
0AH
Interface 0, alternate setting 1 has one interrupt endpoint, IN1, which has a maximum
packet size of 16 and a polling interval of 10 ms.
EZ-USB TRM v1.9
Chapter 5. EZ-USB CPU
Page 5-15