XR22417 Datasheet, PDF (11/17 Pages) Exar Corporation – USB 2.0 7-Port Hub

XR22417
Applications Information (Continued)
Port Status Indicators
Seven port indicator (LED1 - LED7) pins, provide status of downstream devices. Ports using LED indicators may configure
status LEDs in a number of configurations in conjunction with the LED_CTL pin. Per the USB 2.0 spec, amber and green
LEDs are used to indicate port status automatically controlled by the USB hub. When the hub is suspended or not yet
configured the LEDs must be off, solid green indicates normal operation, and amber or flashing green and/or amber indicate
various error conditions as defined in the specification. The TEST#/SDA and LED1/SCL pins may also be connected to an
external EEPROM.
TEST#/SDA
Green
LED1/SCL
Amber
LED2
Green
LED3
Amber
XR22417
LED4
Green
LED5
Amber
LED6
Green
LED7
Amber
SDA _EEPROM
SCL
A2
A1
A0
Green
Amber
Green
Amber
Green
Amber
LED_CTL
470
Hub active
indicator (optional)
Red
Figure 3. Port and Hub Status Indicators
REV1A
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