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Philips Semiconductors
ISP1521
Hi-Speed USB hub controller
Product data Rev. 03 — 24 November 2004 13 of 53
9397 750 13702
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
9. Configuration selections
The ISP1521 is configured through I/O pins and, optionally, through an external
I
2
C-bus, in which case the hub can update its configuration descriptors as a master or
as a slave.
Table 3 shows the configuration parameters.
[1] Multiple ganged power mode is reported as individual power mode; refer to the USB 2.0 specification.
[2] When the hub uses the global overcurrent protection mode, the overcurrent indication is through the wHubStatus field bit 1 (overcurrent)
and the corresponding change bit (overcurrent change).
Table 3: Configuration parameters
Mode and selection Option Configuration method
Pin control Software control
Control pin Reference Affected field Reference
Number of downstream
facing ports
2 ports
3 ports
4 ports
5 ports
6 ports
7 ports
DM1/DP1 to
DM7/DP7
see Section 9.1.1 bNbrPorts0 see Tabl e 22
Power switching mode none
ganged
multiple ganged
[1]
individual
PSW1_N to
PSW7_N
see Section 9.1.2 wHubCharacteristics:
bits D1 and D0
see Tabl e 22
bPwrOn2PwrGood:
time interval
Overcurrent protection
mode
none
global
[2]
multiple ganged
individual
NOOC and
OC1_N to
OC7_N
see Section 9.1.3 wHubCharacteristics:
bits D4 and D3
see Tabl e 22
Non-removable ports any port can be
non-removable
AMBn_N see Section 9.1.4 wHubCharacteristics:
bit D2 (compound hub)
see Tabl e 22
DeviceRemovable:
bit map
Port indicator support no
yes
all GRNn_N see Section 9.1.5 wHubCharacteristics:
bit D7
see Tabl e 22