scsi interface specification - Plasmon

SCSI COMMANDS AND STATUSSTATUSSTATUSA status byte is sent from the LaserDrive to the Initiator during the STATUS phase at the termination ofeach command as specified in Table 4 unless the command is cleared by an ABORT message, by a BUSDEVICE RESET message, a hard RESET condition, or by an unexpected BUS FREE condition.Table 4. Status Byte ValuesSTATUS BYTE VALUE00H02H04H08H18H22HSTATUS REPRESENTEDGOODCHECK CONDITIONCONDITION METBUSYRESERVATIONCONFLICTCOMMAND TERMINATEDGOODCHECK CONDITIONCONDITION METBUSYRESERVATION CONFLICTCOMMAND TERMINATEDThis status indicates that the LaserDrive has successfully completedthe command.Any error, exception or abnormal condition that causes sense data tobe set will cause a CHECK CONDITION status. The REQUESTSENSE command should be issued following a CHECK CONDITIONstatus to determine the nature of the condition.The MEDIA SCAN command will return this status when the searchcondition is satisfied.The LaserDrive is busy. This status is returned whenever theLaserDrive is unable to execute a command from an otherwiseacceptable Initiator. The LaserDrive responds to drive mechanismaccessingcommands with BUSY while a spin up or spin down is inprogress. BUSY is also returned when a command is in progress andthis command cannot be stored for later execution (e.g.,disconnect notpermitted). The normal recovery action is to re-issue the commandlater.This status is returned whenever a SCSI device attempts to access theLaserDrive while it is reserved for another SCSI device (seeRESERVE and RELEASE UNIT commands). The normal Initiatorrecovery action is to re-issue the command later.This status shall be returned whenever the LaserDrive terminates thecurrent I/O process after receipt of a TERMINATE I/O PROCESSmessage.97653978 HPage 23