Legal Phase Sequences - Tandberg Data SLR7-140 PROGRAMMER Manual

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CAPS
<initiator-part>
<message-out>
Tandberg Data
Arbitration and Selection are always controlled by the
Initiator. Once
Target controls
information transfer phases. If the Initiator wants to
interrupt by sending a message to the Target, it may
assert ATN.
3.2.1.

Legal Phase Sequences

The sequences depend on the command(s) and the use of
the ATN condition
command sections
possible sequences of each command.
3.2.1.1. Notation
The notation used in the sequences is called Backus-Naur
Form or BNF. The elements of the notation used in this
manual are as follows:
Rewriting rule or production. This symbol is read as 'is
defined as' or 'can be replaced by'.
Or. This symbol separates alternative definitions.
Angle brackets are used to delimit the name of a defined
sequence, e.g. <sequence>. Where it is defined, the name
of a sequence is set in boldface.
Braces are used to denote a possible repetition of the
enclosed symbols – one ore more times.
The names of the different SCSI-bus phases are set in
capital letters.
3.2.1.2. Sequence Elements
The sub-sequences or sequence elements shown below will
be used in the different command sections to describe
the actual sequences that are possible for each command.
::= BUS-FREE ARBITRATION SELECTION
The Initiator initiates
waiting for the BUS FREE phase, then by arbitrating for
the bus and – when the bus has been won – finally by
selecting the Drive.
::= MESSAGE-OUT |
MESSAGE-OUT <message-out> |
MESSAGE-OUT MESSAGE-IN <message-out> |
MESSAGE-OUT BUS-FREE
3-4 Tandberg SLR Product Line SCSI Functional Specifications
the Target is selected
the phase sequencing
by the Initiators.
(sections 8 through
a new
Logical Characteristics
however,
between
The different
31) detail
connection by first
the
the
the