Fujitsu MAA3182FC Series Manual page 215

Bit 1 (LoEj (load/eject) of byte 4 of the CDB is the exclusive bit which controls devices with
replaceable recording media, and it has no meaning for the IDD. The IDD disregards the value
specified in this bit and controls starting and stopping of the spindle motor in accordance with
the "Start" bit only.
It is possible to select the disk drive's spindle motor starting mode through the T-CARD or
enclosure I/F.
If this command in the stop instructions is issued when the spindle motor has already started,
or even if this command is issued in the stop instruction after the spindle motor has already
been stopped, this command terminates normally.
When this command ("Start"/"Stop" bit = "1") is issued in the start instruction, the command
termination timing can be varied as shown below by the specification in the "Immed
(Immediate) " bit in bit 0 of CDB byte 1.
a. If the "Immed" bit is "1" and it is Start instruction.
Simply by performing a spindle motor start instruction, without waiting for the disk drive
to enter the READY state, the "GOOD" status is reported and the command's execution is
terminated. The operation of the spindle motor when the "Immed" bit is specified
corresponding to the various spindle motor conditions (normal system) is shown below.
•
When Start Unit is Issued
•
When the motor is in the stopped state and Start Unit is issued (First time).
→
•
When the motor is turning (accelerating) and Start Unit is issued (immediately
after the "Immed" bit specified issue of the Start Unit command).
→
•
When the motor is turning (turning at the rated speed) and Start Unit is issued.
→
•
When the motor is turning (decelerating) and Start Unit is issued (just after the
specification in the "Immed" bit issues Stop Unit).
→
b. If the "Immed" bit is "1" and it is a Stop Instruction
Simply by executing the spindle motor stop instruction, the "GOOD" status is reported
without waiting for the disk drive to enter the Not Ready state, then command execution
terminates.
4 - 72
Simply by performing motor start, the "GOOD" status is reported.
After waiting for the motor to reach the rated speed, the "GOOD" status is
reported (this takes time).
If it is turning at the rated speed, nothing happens, and the "GOOD" status
is reported instantly.
After stopping completely, the motor starts, then the command terminates
(this takes time).
C141-E054-02EN