4 signal source -10 – FUJITSU C150-E049-02EN User Manual

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M3099GX/GH OEM Manual

Table 3.4 Signal Source

DB(7,0)
DB(P)

None
S ID
Init
Targ
Init
Targ
Init
Targ
Targ
Init

Bus Phase

BUS FREE
ARBITRATION
SELECTION
RESELCTION
COMMAND
DATA IN
DATA OUT
STATUS
MESSAGE IN
MESSAGE OUT

ACK,
ATN

None
None
Init
Init
Init
Init
Init
Init
Init
Init

C/D, I/O,
MSG,
REQ

None
None
None
Targ
Targ
Targ
Targ
Targ
Targ
Targ

SEL

None
Win
Init
Targ
None
None
None
None
None
None

BSY

None
All
I&T
I&T
Targ
Targ
Targ
Targ
Targ
Targ

All:

The signal shall be driven by all SCSI devices that are actively
arbitrating.

S ID: A unique data bit (the SCSI ID) shall be driven by each SCSI

device that is actively arbitrating; the other seven data bits shall be
released (i.e., not driven) by this SCSI device. The parity bit
(DB(P)) may be released or driven to the true state, but shall never
be driven to the false state during this phase.
The signal shall be driven by the initiator, target or both, as
specified in the SELECTION phase and RESELECTION phase.

Init:

If driven, this signal shall be driven only by the active initiator.

None: The signal shall be released; that is, not be driven by any SCSI

device. The bias circuitry of the bus terminators pulls the signal to
the false state.

Win:

The signal shall be driven by the one SCSI device that wins
arbitration.

Targ: If the signal is driven, it shall be driven only by the active target.

#03.pm5

98.2.22, 1:31 PM

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