Product Manual - Hawk 1LP Family SCSI-2 (Volume 1), Rev. A
15
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Notes.
[1]
Configuration Select Header (see Figure 10.1-1 and 10.2.1-1).
[2]
This connection is only available on ST31200NC and ST3620NC models.
Figure 5.7-1. Synchronized drive interconnect diagram
The servo/read-write LSI on the master drive provides the reference signal (). It is a 90.18 Hz crystal
generated signal. The signal is normally false/negated (nominal 0 V) and makes a transition to the true/asserted
(n5 V) level to indicate the reference position during the revolution period. The trailing (falling) edge
of the reference signal is used by the master and the slave drives to phase lock their spindles. A maximum of
10 seconds is allowed for a slave to synchronize with the reference signal. The signal (available on
J7-6. See Figure 5.7-1) of each synchronized drive shall occur 85.2 usec +20 usec after the signal.
The signal (internal to drive) of each synchronized drive shall occur 85.2 usec ±20 usec after the
signal. Figure 5.7-2 shows the characteristics of the reference signal.
Master Sync
Source
Host
(or other drive)
Spindle
Control
Drive 1
+5V
R
T
J6
6
5
Spindle
Control
Drive 2
+5V
R
T
J6
6
5
Spindle
Control
Drive n
+5V
R
T
J6
6
5
Sync Interface
SCSI Bus
System
Interface
J1
37
[2]
[1]
J1
37
[2]
[1]
J1
37
[2]
[1]
J1
Bottom side of PCB
J2
J7
32
2
6
4
