Jumper Configurations; Parity Enable Option - Seagate ST3285N Product Manual

22 ST3655 Family SCSI Drives Product Manual, Rev. A
2.8.2.1 Single-ended drivers and receivers
The drive uses single-ended drivers and receivers. Schematic repre-
sentations of the removable terminator resistor packs are shown in
Figure 4 on page 21 and Figure 5 on page 21.
• Transmitter characteristics. The drive uses an ANSI SCSI-compat-
ible, open-collector, single-ended driver. This driver is capable of
sinking a current of 48 mA with a low-level output voltage of 0.4 volts.
• Receiver characteristics. The drive uses an ANSI SCSI single-
ended receiver with hysteresis gate or equivalent as a line receiver.
The loss in the cable is defined as the difference between the voltages
of the input and output signals, as shown below:
Logic level Driver output (x)
≤
Asserted (1)
0.0V
≤
Negated (0)
2.5V

2.9 Jumper configurations

The jumper blocks are shown in Figure 6 on page 24 and Figure 7 on
page 25. The jumper applications and part numbers are listed below:
Jumper size Part number
2-mm Seagate PN 13211-001
Du Pont PN 89133-001,
Methode PN 8618-202-70,
or equivalent
0.1-inch Seagate PN 10562-001
Du Pont PN 86214,
Molex™ PN 87092-3013,
or equivalent

2.9.1 Parity enable option

When a jumper is installed on pins 1 and 2 of the options jumper block,
the parity bit is used. This is the default. When a jumper is not installed
on pins 1 and 2 of the options jumper block, the parity bit is not used.
Receiver input (x)
≤
x 0.4V 0.0V
≤
x 5.25V 2.0V
Application
J5 and J8 only
All jumper blocks
except J5 and J8
≤ ≤
x 0.8V
≤ ≤
x 5.25V