Quantum Audio Travan 40 Tape Drive STT3401A - Manual (Page 93)

ATAPI Interface Chapter 5
Seagate Travan 40 Product Manual Page 85
VERIFY (Group 0, Op. Code 13)
The VERIFY command performs a Verification Check on a specified number of data
blocks on the tape without involving the Host. Verification starts at the present
position of the tape and continues for the specified number of blocks. If a data block
cannot be verified by CRC recovery then ECC and read retries will be employed in
an attempt to recover the data. The command terminates as a result of one of the
following conditions:
•
The specified number of blocks has been verified.
•
A Filemark or Setmark has been detected.
•
The End-of-Data has been reached.
•
A Verification failure occurred.
Upon termination, the tape is positioned to read the block following the last data
block or Filemark read correctly.
CDB for VERIFY command
Data Bits
Byte 7 6 5 4 3 2 1 0 Hex
0 0 0 0 1 0 0 1 1 13
1 0 0 0 0 0 IMM BytCmp FBM 0X
2
3
4 MSB
Length Of Verification
LSB
XX
XX
XX
5 0 0 0 0 0 0 0 0 00
IMM: When the IMMEDIATE bit is set to 0, status will be returned to the Host when
the VERIFY operation is completed. When set to 1, the status will be returned to the
Host as soon as the VERIFY operation is initiated.
NOTE: The ATAPI interface does not have an IMM bit or functional equivalent. The
DSC and BUSY bits in the Host taskfile status register indicate bus and
command status.
BytCmp: When the Byte Compare bit is set to 0, the drive will perform a media data
recoverability verification only. A Byte Compare bit set to 1 indicates the drive will
perform a byte-by-byte compare between data read from the media and data sent
from the Host. BytCmp=1 is not supported.
FBM: The Fixed Block Mode bit (FMB) set to 1 indicates fixed block mode operation.