Philips ISP1122A Product Data page 17

Philips Semiconductors
9397 750 08958
Product data
Table 14: Hub descriptor
Values in square brackets are optional.
Offset Field name
(bytes)
0 bDescLength
1 bDescriptorType
2 bNbrPorts
3 wHubCharacteristics
5 bPwrOn2PwrGood
6 bHubContrCurrent
7 DeviceRemovable
8 PortPwrCtrlMask
[1] ISP1122A always reports power management status on an individual basis, even for ganged/global
modes. This is compliant with USB Specification Rev. 1.1 .
[2] Condition with no overcurrent detection is reported to the host.
[3] Value in units of 2 ms.
Table 15: String descriptors
String descriptors are optional and therefore disabled by default; they can be enabled through
an external EEPROM.
Offset Field name
(bytes)
String descriptor (0): language ID string
0 bLength
1 bDescriptorType
2 bString
String descriptor (1): manufacturer string
0 bLength
1 bDescriptorType
2 bString
String descriptor (2): product string
0 bLength
1 bDescriptorType
2 bString
[1] Unicode encoded string.
Rev. 03 — 30 October 2001
Size Value Comments
(bytes) (Hex)
1 09 descriptor length = 9 bytes
1 29 type = HUB
1 05 to 02 number of enabled downstream ports;
selectable by DP/DM strapping
2 09, 00 individual power switching
overcurrent protection active
(modes 0, 1, 3, 4, 5, 7)
11, 00 individual power switching
overcurrent protection (modes 2, 6)
[3]
1 32 100 ms (default; modes 0, 1, 2, 4, 5, 6)
00 0 ms (default; modes 3, 7)
[FA] 500 ms (using an external EEPROM;
modes 0, 1, 2, 4, 5, 6); see
1 64 maximum hub controller current
(100 mA)
1 00 all devices removable
1 FF must be all ones for compatibility with
USB Specification Rev. 1.0
Size Value Comments
(bytes) (Hex)
1 04 descriptor length = 4 bytes
1 03 type = STRING
2 09, 04 LANGID code zero
1 2E descriptor length = 46 bytes
1 03 type = STRING
[1]
44 UC "Philips Semiconductors"
1 10 descriptor length = 16 bytes
1 03 type = STRING
[1]
14 UC "ISP1122"
ISP1122A
USB stand-alone hub
[1]
,
[1]
, no
Table 23
© Koninklijke Philips Electronics N.V. 2001. All rights reserved.
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