Fujitsu MAP3735NC/NP Computer Drive User Manual


 
3-8 C141-E166
(1) Gaps (G1, G2, G3)
The gap length at the time of formatting (initializing) is listed in Figure 3.6. No pattern is written
on the gap field.
(2) PLO Sync
In this field, pattern X'00' in the length in bytes listed in Figure 3.6 is written.
(3) Sync Mark (SM1, SM2)
In this field, special pattern in the length in bytes listed in Figure 3.6 is written. This special
pattern indicates the beginning of the data field.
(4) Data field (DATA1-DATA4)
User data is stored in the data field of the sector. The length of the data field is equal to that of the
logical data block which is specified with a parameter in the MODE SELECT command. Any
multiple of 4 between 512 and 528 bytes can be specified as the length.
(5) BCRC
It is a 4-byte error detection code. Errors in the ID field. Single burst errors with lengths of up to
32 bits for each logical block can be detected.
(6) ECC
This is the 60-byte code that allows detection and correction of errors in the data field, which is
capable of correcting the single burst error up to 240 bits max. on the fly.
(7) PAD
A specified length of x‘00’ pattern shown in Figure 3.6 is written in this field. This field includes
the variation by rotation and circuit delay till reading/writing.