2)Application requirements / processing

When WRITE/WRITE EXTENDED command detects any Servo error (e.g. Write offtrack error) and cannot be recovered within pre-determined retry number (specified in Mode Parameter). For the sectors around defective Servo, alternate blocks are allocated and the data of this WRITE commands are re-written.

Sectors to be made AWRE shall be following:

-the sector where the error occurs and the latter sectors and,

-the sectors whose data are logically continual and stored in Cache,

-the sectors which will be processed in this Write command and,

-the sectors which locate between erroneous Servo −1 and +1 (including Split sector)

This function is also applied for the sector that has already been re-assigned.

Remark:

When a write protection is prohibited through the setting terminal, the auto alternate block allocation processing specification is disabled.

IMPORTANT

Automatic alternate block allocation is made up to the following quantities during the execution of one command:

ARRE = Twice

AWRE (Type 1) = 16 times

AWRE (Type 2) =Maximum number which can be processed within the recovery time limit

If more than the above mentioned defective block is detected, the alternate block assignment processing for the first defective block is executed but the alternate block assignment processing for the second one is not executed and the command being executed terminates. However, the initiator can recover the twice error by issuing the same command again.

When an error is detected in a data block in the data area, recovery data is rewritten and verified in automatic alternate block allocation during the execution of the READ or READ EXTENDED command. Alternate block allocation will not be made for the data block if recovery is successful.

Example: Even if the data error which is recoverable by the WRITE LONG command is simulated, automatic alternate block allocation will not be made for the data block.

C141-E270

45

Page 49
Image 49
Fujitsu MBA3073NC, MBA3073NP, MBA3300NP, MBA3147NC, MBA3300NC, MBA3147NP manual C141-E270