Sector Number Register; Status Register; Table 64. Status Register - Hitachi 7K400 - Deskstar Hard Drive Specifications

9.13 Sector Number Register

This register contains the starting sector number for any disk data access for the subsequent command. The sector
number is from one to the maximum number of sectors per track.
In LBA mode, this register contains Bits 0–7. At the end of the command this register is updated to reflect the cur-
rent LBA Bits 0–7.
When 48-bit commands are used, the "most recently written" content contains LBA Bits 0-7 and the "previous con-
tent" contains Bits 24-31.

9.14 Status Register

Table 65: Status Register
7 6
BSY DRDY
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. Bit 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 Device Ready. RDY=1 indicates that the device is capable of responding to a command. RDY
(RDY) will be set to zero during power on until the device is ready to accept a command. If the device
detects an error while processing a command, RDY is set to zero until the Status Register is read
by the host, at which time RDY is set back to one.
DF Device Fault. This product does not support DF bit. DF bit is always zero.
DSC Device Seek Complete. If DSC=1, it indicates that a Seek has completed and the device head is
settled over a track. Bit 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 the device in spite of the drive not spinning up.
DRQ Data Request. Bit 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 Corrected Data. Always 0
(COR)
5 4 3
DSC/
DF DRQ
SERV
Deskstar 7K400 Hard Disk Drive Specification
2 1 0
CORR IDX ERR
72