Fujitsu MBA3073 SERIES Technical Manual page 113

When the ATN signal becomes true in the COMMAND phase, the TARG shall start the
MESSAGE OUT phase immediately after a part or all bytes of command (CDB) has been
transferred.
When the ATN signal becomes true in the DATA phase, the TARG shall start the MESSAGE
OUT phase immediately after the DATA phase. However, the TARG can enter the
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.
If SPI information unit transfers are disabled and an ATN signal becomes true in the
RESELECTION phase, the TARG will enter MESSAGE OUT phase after the TARG has sent
its IDENTIFY message for that RESELECTION phase.
When the ATN signal becomes true in the information unit transfer, other than a SPI data stream
information unit, the TARG will enter MESSAGE OUT phase at the completion of the
current SPI information unit (i.e., after receiving all the ACKs from the INIT for the current
SPI information unit).
When the ATN signal becomes true in the information unit transfer, other than a SPI data stream
information unit, the TARG will enter MESSAGE OUT phase at the completion of the
current SPI information unit (i.e., after receiving all the ACKs from the INIT for the current
SPI information unit).
the ATN signal becomes true between SPI information units the TARG will enter MESSAGE
OUT phase at the completion of the next SPI information unit.
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.
1-33 C141-C007