4-Port USB 2.0 Controller

Datasheet

SMSC USB20H04

Page 19

Revision 1.63 (03-30-07)

DATASHEET

Each port’s indicator must be located in a position that obviously associates the indicator with the port. The

color and state of the LED is used to provide status information to the user.

Two different modes of operation are supported for the port indicators: automatic mode and manual mode.

The USB20H04 defaults to automatic mode upon power-up. In automatic mode, the USB20H04 controls

the color of the indicator LED as described in Table 7.1 - Automatic Mode Port Indicators.

Table 7.1 - Automatic Mode Port Indicators

COLOR

DEFINITION

Off

Disconnected, Disabled, Not

Configured, Resetting, Testing,

Suspending, or Resuming

Amber

Over Current Condition

Green

Enabled, Transmit, or TransmitR

In manual mode, the host controls the color and state of the indicator LED by sending a command to the

USB20H04 to put the LED in a particular state.

This is described in Table 7.2 - Manual Mode Port

Indicators.

Table 7.2 - Manual Mode Port Indicators

COLOR

DEFINITION

Off

Not Operational

Amber

Error Condition

Green

Fully Operational

Blinking

Off/Green

Software Attention

Blinking

Off/Amber

Hardware Attention

The USB20H04 can be configured to either support or not support port indicators. If port indicators are not

included in the hub design, disable this feature in the configuration.