20H04 Datasheet, PDF (34/38 Pages) SMSC Corporation – 4-PORT USB2.0 HUB CONTROLLER

4-Port USB2.0 Hub Controller
Datasheet
Table 9.7 - Interface Descriptor (present if multiple-TT)
OFFSET
HIGH
SPEED
0
09h
1
04h
2
00h
3
01h
4
01h
5
09h
6
00h
7
02h
8
00h
FIELD NAME
DESCRIPTION
bLength
bDescriptorType
bInterfaceNumber
bAlternateSetting
bNumEndpoints
bInterfaceClass
bInterfaceSubClass
bInterfaceProtcol
bInterface
Size of this descriptor in bytes
INTERFACE Descriptor Type
Number of this interface
Value used to select this alternate setting for
the interface
Number of endpoints used by this interface (not
including endpoint 0)
Class code assigned by USB for Hubs
Subclass code assigned by USB
Protocol code assigned by USB
Index of string descriptor describing this
configuration (string not supported)
OFFSET
0
1
2
Table 9.8 - On-The-GO (OTG) Descriptor
FULL
SPEED
HIGH SPEED
03h
03h
09h
09h
01h
01h
FIELD NAME
bLength
bDescriptorType
wMaxPacketSize
DESCRIPTION
Size of this descriptor in bytes
OTG Descriptor Type
Attribute Fields:
D[7:2] = Reserved
D1: HNP Support (not supported)
D0: SRP Support.
OFFSET
0
1
2
3,4
5
Table 9.9 - Class-Specific Hub Descriptor (Full-Speed and High-Speed)
FIELD NAME
Length
Descriptor Type
NbrPorts
HubCharacteristics
PwrOn2PwrGood
VALUE
09h
29h
user
user
user
DESCRIPTION
Size of this Descriptor.
Hub Descriptor Type.
Number of downstream facing ports this Hub
supports. Derived from OEM value defined in
EEPROM or SMBus load. See Section 11.23.2.1 in
the USB Specification.
Note: If Dynamic Power is enabled, and the
SELF_PWR pin is low (indicating Bus Power
Operation), then ports 3 & 4 are not available and
either a value of 1 is reported if the OEM value is 1
or a value of 2 is reported if the OEM value is 2, 3
or 4.
Defines several characteristics that are derived
from OEM values. Also defines TT Think Time
(fixed at a value of 00b for 8FS bit times max).
Time (in 2 ms intervals) from the time the power-on
sequence begins on a port until power is good on
that port. Derived from OEM value.
Revision 1.63 (10-14-04)
Page 34
DATASHEET
SMSC USB20H04