1.7 Command Processing ExceptionsC141-C010 1-27Table 1.4 Outline of SCSI Bus Error Recovery ProcessingItem Type of Error Error Recovery Processing1 MESSAGE OUT phase parity error Retry the erroneous phase up to 3times max / "CHECK CONDTION"Status2 COMMAND phase parity error Retry the erroneous phase up to 3times max / "CHECK CONDTION"Status3 DATA OUT phase parity error "CHECK CONDTION" Status4 Received INITIATOR DETECTED ERROR message. Retry the erroneous phase up to 3times max / "CHECK CONDTION"Status5 Received MESSAGE PARITY ERROR message. Re-execute RESELECTION phase6 RESELECTION phase time-out(2) Recovery procedures for disk drive errorsThe IDD executes error recovery listed in Table 1.5 for an error detected during access to data on thedisk. Note that the recovery increases command processing time because of rotation delay forrepositioning to the data block on the disk or initialization of the positioning control system.The INIT can use the MODE SELECT parameter Page 1 (read/write error recovery parameter), Page 7(verify error recovery parameter), and Page 21 (additional error recovery parameter) to control the retrycount. However, use the default value specified by the IDD in general operation.Table 1.5 Outline of disk drive error recovery processingItem Type of Error Error Recovery Processing1 Seek Error Rezero (Return to Zero Cylinder), readjustment of positioningcontrol system, and repositioning to the data block.2 Uncorrectable Data Error Reread3 Correctable Data Error Correct by ECC.Note:The execution start timing of this automatic readjustment operation generally cannot bepredicted by the INIT. The automatic readjustment operation is performed when there are nocommands being executed or in the queue, but execution of commands issued immediately afterthe IDD starts the readjustment operation, are forced to wait until the readjustment operation iscompleted.
