
SATA Technical Overview 51
2.5.4 Device Register
The Device Register (previously Device/Head Register) (see Tables 2.17 and 2.18) has two bits that may
be used. You will have to look at each command usage model to determine if these bits need to be set.
Table 2.17 Device Register (ATA-8)
Register 76543210
Error
SENSE KEY (0h-Fh) obsolete ABRT EOM
ILI
CMDTO
Sector Count
LBA Low
LBA Mid
LBA High
Device obsolete LBA obsolete DEV Reserved
Status
BSY DRDY DF/SE DWE DRQ AE 1 CC/ERR
Note: LBA—Used to select LBA or CHS addressing – always 1 in ATA-8.
DEV—Selects master or slave device – ATA emulation mode only.
2.6 CHS and LBA Addressing
2.6.1 CHS Address