User Manual

SCSI Commands Reference Manual, Rev. J 429

www.seagate.com Parameters for direct access devices

TB (Transfer Block) bit

0 A transfer block (TB) bit set to zero specifies that the device server shall not transfer a logical block to the data-in buffer if the logical

block is not recovered within the recovery limits specified.

1 A TB bit set to one specifies that the device server shall transfer a logical block to the data-in buffer before returning CHECK CONDITION

status if the logical block is not recovered within the recovery limits specified. The data returned in this case is vendor-specific. The TB bit

does not affect the action taken for recovered data.

RC (Read Continuous) bit

0 A read continuous (RC) bit set to zero specifies that error recovery operations that cause delays are acceptable during the data transfer.

Data shall not be fabricated.

1 An RC bit set to one specifies the device server shall transfer the entire requested length of data without adding delays to perform error

recovery procedures. This implies that the device server may send data that is erroneous or fabricated in order to maintain a continuous

flow of data. The device server shall assign priority to the RC bit over conflicting bits within this byte.

NOTE Fabricated data may be data already in a buffer or any other vendor-specific data. The RC bit may be

used in image processing, audio, or video applications.

EER (Enable Early Recovery) bit

1 An enable early recovery (EER) bit set to one specifies that the device server shall use the most expedient form of error recovery first.

0 An EER bit set to zero specifies that the device server shall use an error recovery procedure that minimizes the risk of error mis-detection

or mis-correction. This bit only applies to data error recovery and it does not affect positioning retries.

PER (Post Error) bit

1 A post error (PER) bit set to one specifies that if a recovered read error occurs during a command performing a read or write operation,

then the device server shall terminate the command with CHECK CONDITION status with the sense key set to RECOVERED ERROR. If the

DTE bit is set to one, then the PER bit shall be set to one

0 A PER bit set to zero specifies that if a recovered read error occurs during a command performing a read or write operation, then the

device server shall perform error recovery procedures within the limits established by the error recovery parameters and only terminate

the command with CHECK CONDITION status if the error becomes uncorrectable based on the established limits.

DTE (Data Terminate On Error) bit

1 A data terminate on error (DTE) bit set to one specifies that the device server shall terminate the data-in or data-out buffer transfer upon

detection of a recovered error.

0 A DTE bit set to zero specifies that the device server shall not terminate the data-in or data-out buffer transfer upon detection of a recov-

ered error.

DCR (Disable Correction) bit

1 A disable correction (DCR) bit set to one specifies that ECC shall not be used for data error recovery.

0 A DCR bit set to zero allows the use of ECC for data error recovery. If the EER bit is set to one, the DCR bit shall be set to zero.