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Abort handling – HP Q153090901 User Manual

Page 14

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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