Hitachi HTS541010G9AT00 - Travelstar 100 GB Hard Drive Specifications page 61

BSY
DRDY
DF
DSC
CORR (COR)
IDX
ERR
Busy. BSY=1 whenever the device is accessing the registers. The
host should not read or write any registers when BSY=1. If the
host reads any register when BSY=1, the contents of the Status
Register will be returned.
Device Ready. RDY=1 indicates that the device is capable of
responding to a command. RDY will be set to 0 during power on
until the device is ready to accept a command.
Device Fault. DF=1 indicates that the device has detected a
write fault condition. DF is set to 0 after the Status Register
is read by the host.
Device Seek Complete. DSC=1 indicates that a seek has completed
and the device head is settled over a track. DSC is set to 0 by
the device just before a seek begins. When an error occurs, this
bit is not changed until the Status Register is read by the
host, at which time the bit again indicates the current seek
complete status.
When the device enters into or is in Standby mode or Sleep mode,
this bit is set by device in spite of not spinning up.
Corrected Data. Always 0.
Index. IDX=1 once per revolution. Since IDX=1 only for a very
short time during each revoltion, the host may not see it set to
1 even if the host is reading the Status Register continuously.
Therefore the host should not attempt to use IDX for timing pur-
poses.
ERR=1 indicates that an error occurred during execution of the
previous command. The Error Register should be read to determine
the error type. The device sets ERR=0 when the next command is
received from the host.
Travelstar 5K100 (Serial ATA) Hard Disk Drive Specification
49