Theory of Device Operation
4-10
C141-E120-02EN
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.
4.6.2 Write circuit
The write data is output from the hard disk controller (HDC) with the NRZ data
format, and sent to the encoder circuit in the RDC. The NRZ write data is
converted from 16-bit data to 17-bit data by the encoder circuit then sent to the
HDIC, and the data is written onto the media.
(1) 16/17 MTR MEEPRML
This device converts data using the 16/17 MTR (Maximum Transitions Run
Length Limited) algorithm.
This code is converted so that a maximum of three 1’s are placed continuously
and so that there are two or fewer 1’s in a 17-bit border.
(2) Write precompensation
Write precompensation compensates, during a write process, for write non-
linearity generated at reading. Table 4.1 shows the write precompensation
algorithm.
Summary of Contents for MHN2100AT - Mobile 10 GB Hard Drive
Page 1: ...C141 E120 02EN MHN2300AT MHN2200AT MHN2150AT MHN2100AT DISK DRIVES PRODUCT MANUAL ...
Page 4: ...This page is intentionally left blank ...
Page 8: ...This page is intentionally left blank ...
Page 10: ...This page is intentionally left blank ...
Page 12: ...This page is intentionally left blank ...
Page 32: ...This page is intentionally left blank ...
Page 38: ...This page is intentionally left blank ...
Page 52: ...Installation Conditions 3 14 C141 E120 02EN Figure 3 16 Example 2 of Cable Select drive drive ...
Page 58: ...Theory of Device Operation 4 6 C141 E120 02EN Figure 4 3 Circuit Configuration ...
Page 76: ...This page is intentionally left blank ...
Page 174: ...Interface 5 98 C141 E120 02EN g d f f d e Figure 5 7 Normal DMA data transfer ...
Page 224: ...This page is intentionally left blank ...
Page 228: ...This page is intentionally left blank ...
Page 230: ...This page is intentionally left blank ...
Page 232: ...This page is intentionally left blank ...
Page 234: ...This page is intentionally left blank ...
Page 235: ......
Page 236: ......