FUJITSU DISK DRIVES MHM215OAT - Manual (Page 64)

4.6 Read/write Circuit
C141-E104-02EN 4-11
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 4.2 shows the write precompensation
algorithm.
Table 4.2 Write precompensation algorithm
Bits Compensation
111001
111010
:
111111
000000
000001
:
010000
:
100000
–7
–6
–1
±
0
+1
+16
+32