3.1 Data Space

Cylinder skew

Head

Cylinder skew

P

Track skew

Head

P+1

Leading logical sector in head p+1

Figure 3.5 Track skew/head skew

The number of physical sectors (track skew factor and head skew factor) corresponding to the skew time varies depending on the logical data block length because the track skew and the head skew are managed for individual sectors. The IDD automatically determines appropriate values for the track skew factor and the head skew factor according to the specified logical data block length. The value can be read out by the MODE SENSE or MODE SENSE EXTENDED command after the track has been formatted.

3.1.4Sector format

Each sector on the track consists of an ID field, a data field, and a gap field which separates them. Figure 3.6 gives sector format examples.

SCT

PLO

 

 

 

 

 

 

 

 

 

 

 

 

SCT

 

 

 

 

SM1

DATA1

SM2

DATA2

BCRC

 

ECC

PAD

 

 

 

 

 

 

 

 

 

 

 

G1

Sync

 

 

G2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SCT

PLO

 

 

 

 

 

 

 

 

Servo

 

 

 

 

 

 

 

SCT

 

SM1

DATA1

SM2

DATA3

PAD

 

 

 

 

 

 

 

PLO

SM1

DATA1

SM2

DATA4

BCRC

ECC

PAD G3

G1

Sync

 

G2

 

 

G1 Sync

 

 

 

Figure 3.6 Sector format

C141-E198

3-7

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Image 43
Fujitsu MAS3735FC, MAS3367FC manual Track skew/head skew, Sector format