Track Format - Fujitsu MAG3182FC SERIES Product Manual

The interval of the sector pulse (length of the physical sector) is decided by multiple of 20MHz
free running frequency. This clock is not equal to the interval of the byte clock for each zone.
Therefore, the physical sector length cannot be described with a byte length.
*1: MAF3364FC, MAG series
(2) Track skew and cylinder skew
To avoid waiting for one turn involved in head and cylinder switching, the first logical data block
in each track is shifted by the number of sectors (track skew and cylinder skew) corresponding to
the switching time. Figure 3.5 shows how the data block is allocated in each track.
At the head switching location in a cylinder, the first logical data block in track t + 1 is allocated
at the sector position which locates the track skew behind the sector position of the last logical
data block sector in track t.
At the cylinder switching location, like the head switching location, the first logical data block in
a cylinder is allocated at the sector position which locates the cylinder skew behind the last
logical sector position in the preceding cylinder. The last logical sector in the cylinder is
allocated when formatting, and is an unused spare sector.
3 - 6
*1
119,700 CLKs (20MHz)
Figure 3.4

Track format

C141-E078-02EN