USB2503 datasheet(23/46 Pages) SMSC

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USB 2.0 High-Speed 4-Port Hub Controller

Datasheet

SMSC USB2514

Revision 1.92 (05-08-07)

DATASHEET

4.3.1.8

PORT_PWR

Port Power Switching: Enables power switching on all ports simultaneously

(ganged), or port power is individually switched on and off on a port- by-port

basis (individual). The ability to support power enabling on a port or ganged

basis is hardware implementation dependent.

0 = Ganged switching (all ports together)

1 = Individual port-by-port switching

BIT

NUMBER

BIT NAME

DESCRIPTION

DYNAMIC

Dynamic Power Enable: Controls the ability of the Hub to automatically

change from Self-Powered operation to Bus-Powered operation if the local

power source is removed or is unavailable (and from Bus-Powered to Self-

Powered if the local power source is restored). {Note: If the local power

source is available, the Hub will always switch to Self-Powered operation.}

When Dynamic Power switching is enabled, the Hub detects the availability

of a local power source by monitoring the external LOCAL_PWR pin. If the

Hub detects a change in power source availability, the Hub immediately

disconnects and removes power from all downstream devices and

disconnects the upstream port. The Hub will then re-attach to the upstream

port as either a Bus-Powered Hub (if local-power is unavailable) or a Self-

Powered Hub (if local power is available).

0 = No Dynamic auto-switching

1 = Dynamic Auto-switching capable

Reserved

5:4

OC_TIMER

OverCurrent Timer: Over Current Timer delay.

00 = 0.1ms

01 = 4ms

10 = 8ms

11 = 16ms

COMPOUND

Compound Device: Allows the OEM to indicate that the Hub is part

of a compound (see the USB Specification for definition) device. The

applicable port(s) must also be defined as having a "Non-Removable

Device".

Note:

When configured via strapping options, declaring a port as non-

removable automatically causes the hub controller to report that it

is part of a compound device.

0 = No

1 = Yes, Hub is part of a compound device

2:0

Reserved

BIT

NUMBER

BIT NAME

DESCRIPTION

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