Avago Technologies LSI53C120 - Manual (Page 25)

LSI20101/LSI20102 SCSI Bus Boards 17
Connecting the Disable SE-A TERM or Disable SE-B TERM pins on J5
to ground turns off the onboard termination for the indicated physical bus.
See
Table 10 .
4.4.4 LEDs and Connector J4
The LSI20102 board contains three LEDs: one bus activity LED and two
SCSI TERMPWR status LEDs.
One green LED reflects the status of the SCSI bus busy signal.
Two yellow LEDs, one for each bus, indicate when TERMPWR is shorted
to ground. For instance, if TERMPWR is grounded somewhere in the
subsystem while TERMPWR is supplied by the board (when U8 switches
SW1 and/or SW2 are ON), the LED will light. See
Table 11 .
Table 10 Termination Control Connector J4
J4-Pin Number Signal Name
1 Disable SE-A TERM
2 GND
3 Disable SE-B TERM
4 GND
Table 11 LED Description
LED Color/Condition Description
CR1 Yellow/ON DIFF, TERMPWR shorted to ground
CR7 Green/ON A-Side, BUSY (SCSI active on Side-A)
1
1. If the SCSI busy signal is active on A-side, it is also active on B-side and vice
versa.
CR10 Yellow/ON SE, TERMPWR shorted to ground