Fujitsu MAN3184 SERIES Specifications page 91

When the ATN signal becomes true in the DATA phase, the TARG shall start the MESSAGE
OUT phase immediately after the DATA phase.
MESSAGE OUT phase any time when necessary. (Data transfer is not interrupted on a
boundary of logical data blocks.) The INIT shall continue the REQ/ACK handshaking (in
DATA phase) until the bus phase is changed.
When the ATN signal becomes true in the STATUS phase, the TARG shall start the
MESSAGE OUT phase after the end of status byte transfer.
When the ATN signal becomes true in the MESSAGE IN phase, the TARG shall start the
MESSAGE OUT phase immediately after the end of current message transfer.
When the ATN signal becomes true in the SELECTION phase, the selected TARG shall start
the MESSAGE OUT phase immediately after the SELECTION phase.
When the ATN signal becomes true in the RESELECTION phase, the TARG shall start the
MESSAGE OUT phase after the end of IDENTIFY message transfer.
During a RESELECTION phase the INIT should only create an attention condition to transmit an
ABORT TASK SET, ABORT TASK, TARGET RESET, CLEAR TASK SET, DISCONNECT,
LOGICAL UNIT RESET, or NO OPERATION message. Other uses may result in ambiguities
concerning the nexus.
In the case of more than one byte message transferred, the INIT should keep the ATN signal
asserted throughout the MESSAGE OUT phase.
Unless otherwise specified, the INIT may negate the ATN signal at any time, that does not violate
the specified setup and hold times, except it must not negate the ATN signal while the ACK signal
is asserted during a MESSAGE OUT phase.
Normally, the INIT negates the ATN signal while the REQ signal is true and the ACK signal is
false during the last REQ/ACK handshake of the MESSAGE OUT phase.
C141-E123-01EN
However, the TARG can enter the
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