Verify Command (13H) - Quantum DLT 8000 Product Manual

5.30 VERIFY Command (13h)

The VERIFY command directs the tape drive to verify one or more blocks beginning with
the next block on the tape. Both CRC and EDCs are validated.
Bit 7
Byte
0
1 Logical Unit Number
(MSB)
2 - 4
5 Unused
Figure 5–101 VERIFY Command Descriptor Block — Data Format
Table 5–100 VERIFY Command Data — Field Descriptions
Field Name
Immed
BC
Fixed
Verification Length
6 5
Operation Code (13h)
Verification Length
Description
Immediate. When set to 1, the VERIFY command completes before
any tape medium movement is done (that is, when the processing
has been initiated.
Byte Check. When set to 0, the tape drive performs an internal
CRC/ECC check of data. No data is transferred to the initiator.
When set to 1, the command is rejected.
This bit specifies whether fixed-length or variable-length blocks are to
be verified.
When set to 0, variable-block mode is requested. A single block is
transferred with the Verification Length specifying the maximum
number of bytes the initiator has allocated for verification.
When the Fixed bit is set to 1, the Verification Length specifies the
number of blocks to be verified. This is valid only if the logical unit is
currently operating in Fixed Block mode.
This field specifies the amount of data to verify, in blocks or bytes as
indicated by the Fixed bit.
Quantum DLT 8000 Tape System
4 3
Reserved Immed
Reserved
SCSI Commands
2 1
BC Fixed
Flag
0
(LSB)
Link
5-219