User Manual

SCSI Commands Reference Manual, Rev. J 85
www.seagate.com Direct Access Block commands (SPC-5 and SBC-4)
3.3.5.7 Physical sector format address descriptor
A format type of 101b specifies the physical sector address descriptor defined in table 50. For the FORMAT UNIT command and the READ DEFECT
DATA commands, this descriptor specifies the location of a defect that is either the length of one track or the length of one sector. For the
Translate Address diagnostic pages, this descriptor specifies the location of a track or a sector.
CYLINDER NUMBER field
The CYLINDER NUMBER field contains the cylinder number.
HEAD NUMBER field
The HEAD NUMBER field contains the head number.
SECTOR NUMBER field
The SECTOR NUMBER field contains the sector number. A SECTOR NUMBER field set to FFFFFFFFh specifies that the entire track is being
described.
For sorting physical sector format address descriptors, the cylinder number is the most significant part of the address and the
sector number is the least significant part of the address. More than one logical block may be described by this descriptor.
Table 50 Physical sector format address descriptor (101b)
Bit
Byte
7 6 5 4 3 2 1 0
0
(MSB)
CYLINDER NUMBER
. . .
2
(LSB)
3
HEAD NUMBER
4
(MSB)
SECTOR NUMBER
. . .
7
(LSB)