IBM DTLA-305040 - Deskstar 41.1 GB Hard Drive, Specifications, Page: 149 / 212

12.17 Read Sectors (20h/21h)
see below Status 0 0 1 0 0 0 0 R Command
- - - - H H H H
Device/Head
1 L 1 D H H H H
Device/Head
V V V V V V V V Cylinder High V V V V V V V V Cylinder High
V V V V V V V V Cylinder Low V V V V V V V V Cylinder Low
V V V V V V V V
Sector Number
V V V V V V V V
Sector Number
V V V V V V V V Sector Count V V V V V V V V Sector Count
see below Error - - - - - - - - Feature
- - - - - - - -
Data
- - - - - - - -
Data
7 6 5 4 3 2 1 0
Register
7 6 5 4 3 2 1 0
Register
Command Block Input
Registers
Command Block Output
Registers
V – 0 – V 0 V 0 V 0 V 0 V 0 V 0
ERR IDX COR DRQ DSC DF RDY BSY AMN T0N ABT 0 IDN 0 UNC CRC
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
Status Register Error Register
Figure 103. Read Sectors Command (20h/21h)
The Read Sectors command reads one or more sectors of data from disk media, then transfers the data
from the device to the host.
The sectors are transferred through the Data Register 16 bits at a time.
If an uncorrectable error occurs, the read will be terminated at the failing sector.
Output parameters to the device
Sector Count The number of continuous sectors to be transferred. If zero is specified, then 256
sectors will be transferred.
Sector Number The sector number of the first sector to be transferred. (L=0)
In LBA mode this register contains LBA bits 0 - 7. (L=1)
Cylinder High/Low The cylinder number of the first sector to be transferred. (L=0)
In LBA mode this register contains LBA bits 8 - 15 (Low), 16 - 23 (High). (L=1)
H The head number of the first sector to be transferred. (L=0)
In LBA mode this register contains LBA bits 24 - 27. (L=1)
R The retry bit. If set to one, then retries are disabled.
Deskstar 40GV & 75GXP hard disk drive specifications
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