LSI U80ALVD - Manual (Page 66)

A-10 Technical Specifications
A.2.3 On-Board LED
On-board LEDs are used to indicate the status of the SCSI bus.
The SCSI Activity LED lights when the SCSI bus is transferring
information.
A.2.4 The SCSI Busy LED
The SCSI Activity LED interface on the LSIU80ALVD is a four-wire
arrangement that allows the user to connect an LED harness to the
board. The buffered GPIO0_FETCH line (maximum output low voltage
0.4 V and minimum output low current 16 mA) is pulled low to complete
the circuit when a harness with an LED is attached. The SCSI Busy LED
connector is J4.
Table A.6 LED Connector J4
Signal Name Pin
LED+ 1
LED − 2
LED − 3
LED+ 4