K6602743
Rev.2
02.12.’02
- 84 -
The data returned in the command block registers is the maximum device size as shown in the following
tables.
- CHS Mode
Maximum sector number and maximum head number are fixed values, and the values are 16 and 63.
Task
File
Registers
7 6 5 4 3 2 1 0
Cylinder High
Maximum Cylinder High
Cylinder Low
Maximum Cylinder Low
Device/Head -
0 -
DRV Maximum
Head
Sector Number
Maximum Sector Number
- LBA Mode
Maximum LBA issued by host is not used for the Maximum LBA in the device. The device adopts logical head
and sector numbers that can be divided, and posts the values to the command block registers.
Task
File
Registers
7 6 5 4 3 2 1 0
Cylinder High
Maximum LBA Bit23 –16
Cylinder Low
Maximum LBA Bit15 – 8
Device/Head -
1 -
DRV
Maximum LBA
Bit27 - 24
Sector Number
Maximum LBA Bit7 - 0
- Identify Device Command and Initial Device Parameter
Number of logical cylinder of Identify device command data word 1 posts the value set via this command.
In case of maximum LBA in LBA mode, the Number of logical cylinder of Identify device command data
word 1 is (maximum LBA)/(16 x 63) for DK23EB-40.
In case of logical head number and SPT changed by Initial Device Parameter command, the Identify
Device Word 54 Number of current cylinders is posted by the following calculation method.
CHS Mode
Current Cylinder = (Maximum Logical Cy 1) x 16 x 63 / (Current Head x Current SPT)
LBA Mode
Current Cylinder = (Maximum LBA +1)/ (Current Head x Current SPT)
Current Head: Identify Device Word 55 Number of current heads
Current SPT: Identify Device Word 56 Number of current sectors per track
