Cypress CY7C656xx Byte 19 Write Protect Byte 20 NumLangs, Byte 21 SupportedStrings, Bit Name

PRELIMINARYCY7C656xx

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

6iInterface (1) The iInterface string index reported in the second interface descriptor (alternate setting 1).

5iInterface (0) The iInterface string index reported in the first interface descriptor (alternate setting 0).

4iConfiguration (high-speed) The iConfiguration string index reported in the configuration descriptor, when operating at high- speed.

3iConfiguration (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.

Document #: 38-08037 Rev. *D Page 15 of 23