Abort handling – HP Q153090901 User Manual
Page 14

Interface Implementation
14
•
A
UNIT ATTENTION
condition is set, based on the type of reset
The drive will respond to
INQUIRY
,
TEST UNIT READY
,
REPORT LUNS
and
REQUEST SENSE
within
250 ms of the reset line being released. The first command from any initiator (other than
INQUIRY
,
REQUEST SENSE
and
REPORT LUNS
) will result in
CHECK CONDITION
status with
UNIT ATTENTION
sense data for the reset. Note that all commands will receive
BUSY
status until the drive has
completed its internal reset.
The Reset button on the front panel and the ACI_RESET_L line on the Automation Controller
Interface are both connected to the Power-Up Reset interrupt on the processor. The effect is
equivalent to power-cycling the drive. The contents of the tape and cartridge memory may not be
consistent after the action and any data in the drive buffer will be lost.
Abort handling
If an abort condition is detected before a command phase completes, the bus is set to bus free and
the command is not executed.
If an abort condition is detected between the end of the command phase and the start of the status
phase, the bus is set to bus free and the processing below is carried out.
If an abort condition is detected during status phase, the bus is set to bus free.
If a command (other than
INQUIRY
for standard data or
REQUEST SENSE
) is received after the
abort but before the drive is ready to process the command, the behavior depends on whether
Disconnects are allowed.
•
If disconnects are allowed, the drive will disconnect and wait until the abort processing has
completed before executing the command.
•
If disconnects are not allowed, a
BUSY
response will be returned.
Command
Abort Processing
ERASE
Long erase is aborted as quickly as possible without corrupting the tape
format. Short erase completes.
INQUIRY
None
LOAD/UNLOAD
Load completes and logically positions the tape at BOT.
Unload is aborted leaving the logical position at BOT unless the operation
is past the “point of no return” in which case the tape is ejected.
LOCATE
The logical position is set back to that at the start of the operation.
LOG SELECT
If data transfer is complete, the command is completed, otherwise no action
is taken
LOG SENSE
None
MODE SELECT
If data transfer is complete, the command is completed, otherwise no action
is taken.
MODE SENSE
None