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Output Parameters To The Device
Feature Current
URG (bit7)
RC (bit6)
NS (bit5)
HSE (bit4)
Stream ID (bit 0..2)
Feature Previous
CCTL (7:0)
Sector Count Current
Sector Count Previous
Sector Number Current
Sector Number Previous LBA (31:24).
Cylinder Low Current
Cylinder Low Previous
Cylinder High Current
Cylinder High Previous
URG specifies an urgent transfer request. The Urgent bit specifies that the command
should be completed in the minimum possible time by the device and shall be
completed within the specified Command Completion Time Limit.
RC specifies Read Continuous mode enabled. If the Read Continuous bit is set to one,
the device shall not stop execution of the command due to errors.
If the RC bit is set to one and errors occur in reading or transfer of the data, the device
shall continue to transfer the amount of data requested and then provide ending status
with BSY bit cleared to zero, the SE bit set to one, the ERR bit cleared to zero, and the
type of error, ICRC, UNC, IDNF or ABRT reported in the error log.
If the RC bit is set to one and the CCTL expires, the device shall stop execution of the
command and provide ending status with the BSY bit cleared to zero, the SE bit set to
one, the ERR bit cleared to zero, and report the fact that the CCTL expired by setting
the CCTO bit in the error log to one.
In all cases, the device shall attempt to transfer the amount of data requested within the
CCTL even if some data transferred is in error.
NS (Not Sequential) may be set to one if the next read stream command with the same
Stream ID may not be sequential in LBA space.
HSE (Handle Stream Error) specifies that this command starts at the LBA of the last
reported error for this stream, so the device may attempt to continue its corresponding
error recovery sequence where it left off earlier.
Stream ID specifies the stream to be read. The device shall operate according to the
Stream ID set by the Read Stream command.
The time allowed for the current command's completion is calculated as follows:
Command Completion Time Limit = (content of the Feature register
Previous) * (Identify Device words (99:98)) microseconds
If the value is zero, the device shall use the Default CCTL supplied with a previous
Configure Stream command for this Stream ID. If the Default CCTL
previous Configure Stream command was defined for this Stream ID, the drive will
ignore the CCTL. The time is measured from the write of the command register to the
final INTRQ for command completion. The device has minimum CCTL value. When the
specified value is shorter than the minimum value, CCTL is set to the minimum value.
Actual minimum CCTL value is described in the "Deviations from Standard" section.
The number of continuous sectors to be transferred low order, bits (7:0)
The number of continuous sectors to be transferred high order, bits (15:8). If zero is
specified in the Sector Count register, then 65,536 sectors will be transferred.
LBA (7:0).
LBA (15:8).
LBA (39:32).
LBA (23:16).
LBA (47:40).
Western Digital Hard Disk Drive OEM Specification
214
is zero, or no
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