Hitachi HDT725025VLA380 Specifications - Page 88

Sector Number Register, Status Register

Page 88 highlights

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 current LBA Bits 0-7. When 48-bit commands are used, the "most recently written" content contains LBA Bits 0-7 and the "previous content" contains Bits 24-31. 9.14 Status Register Table 55: Status Register 7 6 5 4 3 2 1 0 DSC/ BSY DRDY DF DRQ CORR IDX ERR SERV 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 (RDY) Device Ready. RDY=1 indicates that the device is capable of responding to a command. 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 DSC DRQ Device Fault. This product does not support DF bit. DF is always zero. 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. 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 (COR) Corrected Data. Always 0 Deskstar T7K500 Hard Disk Drive Specification 74

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Deskstar T7K500 Hard Disk Drive Specification
74
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 55: 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
7
6
5
4
3
2
1
0
BSY
DRDY
DF
DSC/
SERV
DRQ
CORR
IDX
ERR
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
(RDY)
Device Ready. RDY=1 indicates that the device is capable of responding to a command. 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 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
(COR)
Corrected Data. Always 0