Hitachi HTS541616J9SA00 Specifications page 47

11.10 Sector Count Register
This register contains the number of sectors of data requested to be transferred on a read or write
operation between the host and the device. If the value in the register is set to 0, a count of 256
sectors (in 28-bit addressing) or 65,536 sectors (in 48-bit addressing) is specified.
If the register is zero at command completion, the command was successful. If not successfully
completed, the register contains the number of sectors which need to be transferred in order to
complete the request.
The contents of the register are defined otherwise on some commands. These definitions are given in
the command descriptions.
11.11 Status Register
7 6
BSY DRDY
Table 28. Status Register
This register contains the device status. The contents of this register are updated whenever an error
occurs and at the completion of each command.
If the host reads this register when an interrupt is pending, it is considered to be the interrupt
acknowledge. Any pending interrupt is cleared whenever this register is read.
If BSY=1, no other bits in the register are valid.
Bit Definitions
BSY 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.
DRDY (RDY) 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.
DF 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.
DSC 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.
DRQ Data Request. DRQ=1 indicates that the device is ready to transfer a word or byte of data
between the host and the device. The host should not write the Command register when
DRQ=1.
CORR (COR) Corrected Data. Always 0.
IDX Index. Always 0
ERR 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 5K160 (SATA) Hard Disk Drive Specification
Status Register
5 4
DF DSC
3 2
DRQ CORR
47/167
1 0
IDX ERR