Hitachi hard disk 0J11285 500 GB 2.5 " 8 MB 0J11285 Ficha De Dados
Códigos do produto
0J11285
Z5K500 OEM Specifications
49
12.4 Sector Addressing Mode
All addressing of data sectors recorded on the device’s media is by a logical sector address. The logical
CHS address for HTE5450xxA7Ex80 is different from the actual physical CHS location of the data sector
on the disk media.
CHS address for HTE5450xxA7Ex80 is different from the actual physical CHS location of the data sector
on the disk media.
HTE5450xxA7Ex80 support both Logical CHS Addressing Mode and LBA Addressing Mode as the sector
addressing mode.
addressing mode.
The host system may select either the currently selected CHS translation addressing or LBA addressing
on a command-by-command basis by using the L bit in the DEVICE register. So a host system must set
the L bit to 1 if the host uses LBA Addressing mode.
on a command-by-command basis by using the L bit in the DEVICE register. So a host system must set
the L bit to 1 if the host uses LBA Addressing mode.
12.4.1
Logical CHS Addressing Mode
The logical CHS addressing is made up of three fields: the cylinder number, the head number and the
sector number. Sectors are numbered from 1 to the maximum value allowed by the current CHS
translation mode but can not exceed 255(0FFh). Heads are numbered from 0 to the maximum value
allowed by the current CHS translation mode but can not exceed 15(0Fh). Cylinders are numbered from 0
to the maximum value allowed by the current CHS translation mode but cannot exceed 65535(0FFFFh).
sector number. Sectors are numbered from 1 to the maximum value allowed by the current CHS
translation mode but can not exceed 255(0FFh). Heads are numbered from 0 to the maximum value
allowed by the current CHS translation mode but can not exceed 15(0Fh). Cylinders are numbered from 0
to the maximum value allowed by the current CHS translation mode but cannot exceed 65535(0FFFFh).
When the host selects a CHS translation mode using the INITIALIZE DEVICE PARAMETERS command,
the host requests the number of sectors per logical track and the number of heads per logical cylinder.
The device then computes the number of logical cylinders available in requested mode.
the host requests the number of sectors per logical track and the number of heads per logical cylinder.
The device then computes the number of logical cylinders available in requested mode.
The default CHS translation mode is described in the Identify Device Information. The current CHS
translation mode also is described in the Identify Device Information.
translation mode also is described in the Identify Device Information.
12.4.2
LBA Addressing Mode
Logical sectors on the device shall be linearly mapped with the first LBA addressed sector (sector 0)
being the same sector as the first logical CHS addressed sector ( cylinder 0, head 0, sector 1).
Irrespective of the logical CHS translation mode currently in effect, the LBA address of a given logical
sector does not change. The following is always true:
being the same sector as the first logical CHS addressed sector ( cylinder 0, head 0, sector 1).
Irrespective of the logical CHS translation mode currently in effect, the LBA address of a given logical
sector does not change. The following is always true:
LBA = ( (cylinder * heads_per_cylinder + heads)
* sectors_per_track ) + sector - 1
where heads_per_cylinder and sectors_per_track are the current translation mode values.
On LBA addressing mode, the LBA value is set to the following register.
Device
<---
LBA bits 27-24
LBA High
<---
LBA bits 23-16
LBA Mid
<---
LBA bits 15- 8
LBA Low
<---
LBA bits 7- 0