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Output Parameters To The Device
Feature Current
URG (bit7)
WC (bit6)
F (bit5)
HSE (bit4)
Stream ID (bit 0..2)
Feature Previous
Sector Count Current
Sector Count Previous
Sector Number Current
Sector Number Previous
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.
WC specifies Write Continuous mode enabled. If the Write Continuous bit is set to
one, the device shall not stop execution of the command due to errors.
If the WC bit is set to one and errors occur in transfer or writing 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, IDNF or ABRT reported in the error log.
If the WC bit is set to one and the Command Completion Time Limit 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 Command Completion Time Limit 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 Command Completion Time Limit even if some data transferred is in error.
F specifies that all data for the specified stream shall be flushed to the media before
command complete is reported when set to one.
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 being written. The device shall operate according to
the Stream ID set by the Write 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)) u seconds
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 is zero, or no
previous Configure Stream command was defined for this Stream ID, the device 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 (31:24).
LBA (15:8).
LBA (39:32).
LBA (23:16).
LBA (47:40).
Western Digital Hard Disk Drive OEM Specification
305
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