Fujitsu MCE3064SS, Product Manual

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C156-E097-01EN 7 - 5
(2) BSY (BUSY)
This signal indicates that the SCSI bus is being used. In the ARBITRATION phase, it indicates
an arbitration request.
(3) SEL (SELECT)
This signal is used by an INIT to select a TARG (SELECTION phase) or by a TARG to reselect
an INIT (RESELECTION phase).
(4) C/D (CONTROL/DATA)
This signal is driven by a TARG to identify the type of information transferred on the DATA
BUS in combination of I/O and MSG signals. (See Table 7.1)
(5) I/O (INPUT/OUTPUT)
This signal is driven by a TARG to specify the information transfer direction on the DATA BUS
or to identify a SELECTION or RESELECTION phase. (See Table 7.1)
(6) MSG (MESSAGE)
This signal is driven by a TARG to indicate that a message is being transferred on the DATA
BUS. (See Table 7.1)
(7) REQ (REQUEST)
This signal is driven by a TARG to indicate a transfer request to an INIT in INFORMATION
TRANSFER phase.
(8) ACK (ACKNOWLEDGE)
This signal is driven by an INIT to indicate a response for REQ signal to a TARG in the
INFORMATION TRANSFER phase.
(9) ATN (ATTENTION)
This signal is driven by an INIT to indicate that the INIT has a message to be transferred to the
TARG and is used to generate an ATTENTION condition.
(10) RST (RESET)
This signal indicates the RESET condition which is used to clear all SCSI devices on the bus.