Table 7.1 Information Transfer Phase Identification - Fujitsu MCM3064SS Product Manual

(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.

Table 7.1 INFORMATION TRANSFER phase identification

C/D I/O
0 0
0 1
1 0
1 1
0 0
0 1
1 0
1 1
C156-E228-02EN
MSG DB7-0, P
0 Data
0 Data
0 Command (CDB)
0 Status
1 –
1 –
1 Message
1 Message
7.2 Interface Signal Definition
Direction
DATA OUT
INIT TARG
DATA IN
INIT TARG
COMMAND
INIT TARG
STATUS
INIT TARG
– not used
– not used
MESSAGE OUT
INIT TARG
MESSAGE IN
INIT TARG
Phase
7-5