USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

BIT

 

 

 

NUMBER

BIT NAME

 

DESCRIPTION

 

 

 

0

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

 

 

 

 

4.2.1.8Register 07h: Configuration Data Byte 2

BIT

 

 

NUMBER

BIT NAME

DESCRIPTION

 

 

 

7

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

 

 

 

6

Reserved

Reserved

 

 

 

5:4

OC_TIMER

OverCurrent Timer: Over Current Timer delay.

 

 

00 = 0.1ms

 

 

01 = 4ms

 

 

10 = 8ms

 

 

11 = 16ms

 

 

 

3

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

Reserved

 

 

 

SMSC USB2512A

17

Revision 1.96 (07-11-08)

 

DATASHEET