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4.5.2 Execution timing of self-calibration
Self-calibration is executed when:
• The power is turned on.
• The disk drive receives the RECALIBRATE command from the host.
• The self-calibration execution timechart of the disk drive specifies self-calibration.
The disk drive performs self-calibration according to the timechart based on the time elapsed
from power-on. The timechart is shown in Table 4.1. After power-on, self-calibration is
performed about every 30 minutes.
Table 4.1 Self-calibration execution timechart
Time elapsed Time elapsed (accumulated)
1At power-on Initial calibration
2About 30 minutes About 30 minutes
3About 30 minutes About 60 minutes
4About 30 minutes About 90 minutes
5About 30 minutes About 120 minutes
6About 30 minutes About 150 minutes
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Every about 30 minutes
4.5.3 Command processing during self-calibration
If the disk drive receives a command execution request from the host while executing self-
calibration according to the timechart, the disk drive terminates self-calibration and starts
executing the command precedingly. In other words, if a disk read or write service is
necessary, the disk drive positions the head to the track requested by the host, reads or writes
data, and restarts calibration.
This enables the host to execute the command without waiting for a long time, even when the
disk drive is performing self-calibration. The command execution wait time is about
maximum 100 ms.