4-Port USB 2.0 Hub Controller

Datasheet

Revision 1.63 (03-30-07)

Page 22

SMSC USB20H04

DATASHEET

Detailed definition of the bits used to program the OEM values are given in Table 8.2 through Table 8.5.

Table 8.2 - Address 6; Config_Byte_3

BIT

FIELD NAME

DESCRIPTION

7

Self-/Bus-Power

Selects either self-powered or bus-powered operation:

0: Self-powered operation.

1: Bus-powered operation.

6

Port Indicators

Selects implementation of port indicators:

0: No port indicators.

1: Port indicators implemented.

5

High-Speed

Disable

Selects whether high-speed operation is disabled:

0: High-/Full-Speed operation.

1: Full-Speed only (High-Speed disabled).

4

Multiple TT Support

Selects whether multiple transaction translators are available:

0: Single TT for all ports.

1: Each port has one TT available (multiple TTs supported).

3

EOP Disable

Selects whether EOP generation of EOF1 is disabled when in

Full-Speed mode:

0: EOP generation at EOF1.

1: EOP generation at EOF1 disabled.

2

Current Sensing

Selects whether current sensing is ganged on all ports, or on an

individual port-by-port basis:

0: Individual port-by-port.

1: Ganged sensing.

1

Power Switching

Selects whether downstream port power switching is ganged on all

ports, or on an individual port-by-port basis:

0: Individual port-by-port.

1: Ganged switching.

0

Compound Device

Selects whether the hub is part of a compound device:

0: Not a compound device.

1: Yes, USB20H04 is part of a compound device.

Table 8.3 - Address 7; Config_Byte_2

The ports may be individually configured to be inactive. However, the order in which ports are set to

inactive is very specific. Port 4 must be the first port configured to be inactive, followed by port 3.

BIT

FIELD NAME

DESCRIPTION

7:4

Non-Removable

Device

Selects which ports include non-removable devices. A one

indicates that the port is non-removable:

Bit 7: Port 4 is non-removable.

Bit 6: Port 3 is non-removable.

Bit 5: Port 2 is non-removable.

Bit 4: Port 1 is non-removable.

All zeroes sets all ports removable.