isp1520 NXP Semiconductors, isp1520 Datasheet - Page 14

• Manufacturer Part Number: isp1520
• Description: Hi-speed Universal Serial Bus Hub Controller
• Manufacturer: NXP Semiconductors

Philips Semiconductors
ISP1520_4
Product data sheet
8.2.1.1 Different conditions on I
8.1.4 Nonremovable port
8.1.5 Port indicator support
8.2.1 Background information on I
8.2 Device descriptors and string descriptors settings using I
A nonremovable port, by definition, is a port that is embedded inside the hub application
box and is not externally accessible. The LED port indicators (pins AMBn_N) of such a
port are not used. Therefore, the corresponding amber LED port indicators are disabled to
signify that the port is nonremovable; see
More than one nonremovable port can be specified by appropriately connecting the
corresponding amber LED indicators. At least one port should, however, be left as a
removable port.
The detection of any nonremovable port sets the hub descriptor to a compound hub.
Table 8.
The port indicator support can be disabled by grounding all green port indicators (all
pins GRNn_N); see
only one port.
Table 9.
The I
consists of two bidirectional lines: SDA for data signals, and SCL for clock signals. Both
these lines must be connected to a positive supply voltage through a pull-up resistor.
The basic I
The I
Not busy — both SDA and SCL remain HIGH.
START — a HIGH-to-LOW transition on SDA, while SCL is HIGH.
STOP — a LOW-to-HIGH transition on SDA, while SCL is HIGH.
Data valid — after a START condition, data on SDA must be stable for the duration of the
HIGH period of SCL.
AMBn_N (n = 1 to 4)
Ground
Pull-up with amber LED
GRN1_N to GRN4_N
Ground
LED pull-up green LED for at least one port
•
•
Data transfer is initiated only when the bus is not busy.
Changes in the data line occur when the clock is LOW, and must be stable when the
clock is HIGH. Any changes in data lines when the clock is HIGH will be interpreted as
control signals.
2
2
C-bus is suitable for bidirectional communication between ICs or modules. It
C-bus protocol defines the following conditions:
Nonremovable port pin configuration
Port indicator support: pin configuration
2
C-bus protocol is defined as:
Table
Rev. 04 — 28 April 2006
2
9. This is a global feature. You cannot disable port indicators for
C-bus
2
C-bus
Table
Nonremovable port
nonremovable
removable
Port indicator support
not supported
supported
8.
© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
Hi-Speed USB hub controller
ISP1520
2
C-bus
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