Hitachi Ultrastar 15K450 (FC-AL) Hard Disk Drive Specification
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19.42 START STOP UNIT (1B)
Table 230: START STOP UNIT (1B)
The START STOP UNIT command is used to spin up or stop the spindle motor.
• Immed bit is to specify
0 status is to be returned at the end of the operation.
1 Good status shall always be returned immediately after command has been received. The TEST UNIT
READY command may be used to determine when the drive becomes ready after a spin-up.
• Power Conditions is not supported by the drive and must be set to 0.
• LoEj is not supported by the drive and must be set to 0.
• Start bit is to specify:
0 stop the spindle
1 start the spindle
Note: Once the drive has become ready (after a power on), the START STOP UNIT command can be used without any
errors regardless of the state of the motor: stopped or spinning.
Byte
Bit
76543210
0 Command Code = 1Bh
1 Reserved = 0 Reserved = 0 Immed
2-3 Reserved = 0
4 Power Conditions = 0 Reserved=0
LoEj
= 0
Start
5 VU = 0 Reserved = 0 FLAG LINK
