Status Register; Table 44. Status Register - Hitachi 7K100 - Travelstar - Hard Drive Specifications

10.13 Status Register

Table 44: 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. 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 0 during power on until the device is ready to accept a command.
DF Device Fault. DF=1indicates 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=1indicates 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 and at that time the bit again indi-
cates 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 the drive 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 Corrected Data. Always 0
IDX Index. IDX=1 once per revolution. Since IDX=1 only for a very short time during each revolu-
tion, 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 bit for timing purposes.
ERR Error. 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 bit ERR=0 when the
next command is received from the host.
5 4 3
DF DSC DRQ
Travelstar 7K100 Hard Disk Drive Specification
2 1 0
CORR IDX ERR
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