Command Specifications

4.1.9 START/STOP UNIT (1B)

Byte

Bit

7

6

5

4

 

3

2

1

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0

 

 

 

 

 

X'1B'

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

0

0

0

0

0

0

0

Immed

 

 

 

 

 

 

 

 

 

 

2

 

0

0

0

0

0

0

0

0

 

 

 

 

 

 

 

 

 

 

3

 

0

0

0

0

0

0

0

0

 

 

 

 

 

 

 

 

 

 

4

 

0

0

0

0

0

0

LoEj

Start

 

 

 

 

 

 

 

 

 

 

5

 

0

0

0

0

0

0

0

0

 

 

 

 

 

 

 

 

 

 

 

This command controls the power condition of the disk drive. For the power condition, see Chapter 2, "Power Condition."

The control of the power condition is performed with the Start bit in bit 0 of the CDB byte 4.

Issuing this command with the Start bit set to "0" transits from the power condition state to the Stopped state. Meanwhile, setting the Start bit to "1" transforms the power condition state from the Stopped state to the Active_Wait state. Setting the Start bit to "1" does not transform the power condition state when it is in a state other than the Stopped state.

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 HDD. The HDD disregards the value specified in this bit and controls the Power Condition in accordance with the "Start" bit only.

Depending on the value specified in the "Immed (immediate)" bit, bit 0 of CDB byte 1, the timing of completion (status byte report) of this command differs as shown below.

a.In the case of the start specification ("Start" bit = "1")

When the Immed bit is "1," the power condition state becomes Active_Wait, the GOOD status is reported, and command execution is completed.

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Fujitsu MBA3300RC, MBC2036RC, MBC2073RC, MBA3147RC, MBA3073RC specifications START/STOP Unit 1B