Command Processing During Self-Calibration; Read/Write Circuit; Read/Write Preamplifier (Hdic) - Fujitsu MHM2100AT - Mobile 10 GB Hard Drive Product Manual

Theory of Device Operation
Table 4.1 Self-calibration execution timechart
1
2
3
4
5
6
7
8
.
.
.
.

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 40 ms.

4.6 Read/write Circuit

The read/write circuit consists of the read/write preamplifier (HDIC), the write
circuit, the read circuit, and the time base generator in the read channel (RDC).
Figure 4.4 is a block diagram of the read/write circuit.

4.6.1 Read/write preamplifier (HDIC)

HDIC equips a read preamplifier and a write current switch, that sets the bias
current to the MR device and the current in writing. Each channel is connected to
each data head, and HDIC switches channel by serial I/O. HDIC generates a write
unsafe signal (WUS) when a write error occurs due to head short-circuits or head
disconnection, that avoids error writing.
4-10
Time elapsed
At power-on
About 5 minutes
About 5 minutes
About 10 minutes
About 10 minutes
About 15 minutes
About 15 minutes
Every about 30
minutes
Time elapsed
(accumulated)
Initial calibration
About 5 minutes
About 10 minutes
About 20 minutes
About 30 minutes
About 45 minutes
About 60 minutes
C141-E104-03EN