12.13 Status Register
ERR
IDX
CORR
DRQ
DSC/
SERV
DF
DRDY
BSY
0
1
2
3
4
5
6
7
Status Register
Figure 64. 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.
The use of bit 4 is command dependent. After the DMA Queued commands it is used as SERV. After any
other commands are reset, it is used as DSC.
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 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. DF = 1 indicates that the device has detected a write fault condition. DF is
set to zero 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 zero 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.
SERV (SRV) Service. SRV is set to one when the device is ready to transfer data after it releases the
bus for execution of a DMA Queued command.
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 zero.
IDX
Index. IDX=1 once per revolution. Since IDX=1 only for a very short time during each
revolution, the host may not see it set to one even if the host is reading the Status
Register continuously. Therefore the host should not attempt to use IDX for timing
purposes.
Deskstar 60 GXP Hard disk drive specification
72
Содержание IC35L020 - Deskstar 20 GB Hard Drive
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