Fujitsu MCM3064SS Computer Drive User Manual


 
SCSI BUS
7-42 C156-E228-02EN
Deskew Delay × 2 (Min)
Deskew Delay
× 2 (Min)
Figure 7.19 ATTENTION condition
The ATTENTION condition generated by the INIT in the
SELECTION phase determines the message level to be used in the
command execution sequence. (Details are explained in Subsection
5.1.3. of “MCD3130SS, MCE3130SS, MCK3130SS, MCM3064SS,
MCM3130SS OPTICAL DISK DRIVES SCSI LOGICAL
INTERFACE SPECIFICATIONS.”) If the ATTENTION condition
is not generated in the SELECTION phase, the TARG uses a
COMMAND COMPLETE message only. The TARG does not
respond to the ATTENTION condition even if it was generated in
the subsequent bus phase. Therefore, the TARG does not enter the
MESSAGE OUT phase.
7.7.2 RESET condition
The RESET condition allows all SCSI devices to immediately release the bus.
RESET has higher priority than any other phases and bus conditions. Any SCSI
device can generate the RESET condition at any time by keeping the RST signal
true for 25 µs (Reset Hold Time) or more. The state of all bus signals except RST
signals are undefined during the RESET condition.