Cypress EZ-USB HX2LP - Manual (Page 15)

CY7C656xx PRELIMINARY
Document #: 38-08037 Rev. *D Page 15 of 23
tems that do not accept this, the IllegalHubDescriptor con-
figuration bit may be set to allow CY7C656xx to accept a
DescriptorType of 0x00 for this command. Default is 0, rec-
ommended setting is 1.
Bit 6: CompoundDevice: Indicates whether the hub is part
of a compound device. This is reported in the HubDescrip-
tor, wHub-Characteristics: b2. Default set to 0.
Bit 5: Fullspeed: Only configures the hub to be a full-speed
only device. Default set to 0.
Bit 4: NoPortIndicators: Turns off the port indicators and
does not report them as present in the HubDescriptor,
wHubCharacteristics b7 field. Default set to 0.
Bit 3: Reserved. Should be set to 0.
Bit 2: GangPowered: Indicates whether the port power
switching is ganged (set to 1) or per-port (set to 0). This is
reported in the HubDescriptor, wHubCharacteristics field,
b4, b3, b1, and b0. Default set to 0.
Bit 1: SingleTTOnly: Indicates that the hub should only sup-
port single Transaction Translator mode. This changes var-
ious descriptor values. Default set to 0.
Bit 0: Reserved. Default set to 0.
Byte 18: AmberPolarity, GreenPolarity, SelfPowerable,
ModulateIndicators, PowerControlPolarity, OverCurrent-
Polarity, OverCurrentMode1, OverCurrentMode2
Bit 7: AmberPolarity—Indicates the polarity of the amber
indicator control.
Bit 6: GreenPolarity—Indicates the polarity of the green in-
dicator control.
Bit 5: SelfPowerable—Indicates whether the hub is capable
of operating in self-powered mode. If ‘0’, the hub is capable
of bus-powered operation only.
Bit 4: ModulateIndicators—If this bit is set, the indicator out-
puts will be modulated by a square wave of programmable
frequency, for power savings. If ‘0’, the outputs will be static.
Bit 3: PowerControlPolarity—If set, the power control out-
puts will be active HIGH. If not set, the power control out-
puts will be active LOW.
Bit 2: OverCurrentPolarity—If set, the over-current inputs
will be active HIGH. If not set, the over-current inputs will
be active LOW.
Bit 1: OverCurrentMode1—Reported as bit 4 of the wHub-
Characteristics field of the hub descriptor. If set to ‘1’, this
bit disables over-current detection.
Bit 0: OverCurrentMode2—Reported as bit 3 of the wHub-
Characteristics field of the hub descriptor. If Bit 1 of this byte
is set to ‘0’, over-current detection is enabled. If this bit (Bit
0) is set to ‘1’, the hub reports over-current on a per-port
basis. If set to ‘0’, the hub reports over-current as the sum-
mation of all ports’ current draw.
Byte 19: Write Protect
Byte 20: NumLangs
Number of supported string languages. CHC supports a
maximum of 31 languages; if this field is set to 0 or a num-
ber larger than 31, all string support will be disabled.
Byte 21: SupportedStrings
This field contains a bitmap of strings supported by the hub.
A set bit indicates that the standard string is supported. A
bit not set indicates that the string is not supported. The hub
controller will return a non-zero index for each string which
is supported, and will return 0x00 for each string not sup-
ported, as indicated by this field. The bits in this field corre-
spond to the following standard strings.
Bit Name Description
7 reserved
6 iInterface (1) The iInterface string index reported in
the second interface descriptor
(alternate setting 1).
5 iInterface (0) The iInterface string index reported in
the first interface descriptor (alternate
setting 0).
4 iConfiguration (high-speed) The iConfiguration string
index reported in the configuration
descriptor, when operating at high-
speed.
3 iConfiguration (full-speed) The iConfiguration string
index reported in the configuration
descriptor, when operating at full-
speed.
2 iSerialNumber The iSerialNumber string index
reported in the device descriptor.
1 iProduct The iProduct string index reported in
the device descriptor.
0 iManufacturer The iManufacturer string index
reported in the device descriptor.