Signal Driving Conditions; Signal Status At Receiving End; Signal Driving Method - Fujitsu MAN3184 SERIES Specifications

1.4.5

Signal driving conditions

(1) Signal status value
Table 1.12 shows the correspondence between the input interface signal level at the receiving end
and its logic state.
Logic state
True, "1", or
asserted
False, "0", negated
or released
(2)

Signal driving method

Two driving methods are available: "OR-tied" type and "non-OR-tied" type as indicated in Table
1.13.
Driving method
Signal status
False (*1)
True
*1 In this manual, the signal is said to be false if one of the following conditions is satisfied.
1. The signal is actually driven by a SCSI device to become false (non-OR-tied type).
2. No SCSI device is driving the signal (OR-tied type or non-OR-tied type).
If the BSY, SEL and RST signals may be driven by two or more SCSI devices simultaneously in
the interface operating sequence, they must be driven in the OR-tied method. All signals except
for SEL, BSY, RST and DB(P_CRCA, P1) are not driven by multiple SCSI devices
simultaneously. However, the DBP signals must be driven false in the ARBITRATION phase. All
signals driven in OR-tied and non-OR-tied method can be mixed on the same signal line of SCSI
bus except for BSY, SEL and RST signals.
1-26
Table 1.12

Signal status at receiving end

Single-ended type signal state
Asynchronous, Fast-
5, Fast-10
Low (less than 0.8
VDC)
High (more than 2.0
VDC)
Table 1.13 Signal driving method
"OR-tied" type
No SCSI device drives a signal.
The signal becomes false when
the terminating resistor circuit
is biased.
A SCSI device drives the signal true
C141-E123-01EN
Fast-20
Low (less than 1.0
VDC)
High (more than 1.9
VDC)
A particular SCSI device drives
the signal false. Otherwise, no
SCSI device drives the signal.
LVD type signal
state
Low (-3.6 to -0.030
VDC)
High (0.030 to 3.6
VDC)
"non-OR-tied" type