TAPE UNIT SCSI COMMANDS M2488 PRODUCT GUIDE
4-68 CG00000-011503 REV. A April 1997
4-3.15 READ BLOCK LIMITS command 05h
The READ BLOCK LIMITS command requests the target’s block length limits for the logical unit.
The READ BLOCK LIMITS data, shown in Table 4-62, is sent during the DATA IN phase of the
command.
4-3.15.1 READ BLOCK LIM ITS CDB Descri ption
READ BLOCK LIMITS is a six-byte command. The bytes are as shown below and described in
Table 4-61. Common fields are described in paragraph 4-3.1 on page 4-4.
Variable and fixed length blocks are supported. Refer to Table 4-62 for the READ BLOCK LIM-
ITS data.
BITS
BYTES 7 6 5 4 3 2 1 0
000000101
1LUN Reserved
2Reserved
3Reserved
4Reserved
5Reserved Flag Link
Note: Changeable fields in the CDB are shaded.
Table 4-61. READ BLOCK LIMITS Field Description
BYTE BIT VALUE DESCRIPTION
0 0-7 05h Operation code.
Table 4-62. READ BLOCK LIMITS Data
BYTE BIT VALUE DESCRIPTION
0 0-7 Reserved.
1-3 040000h (262,144) The maximum block length is the maximum number of bytes the host can
request via a read or write operation.
The maximum block length conforms to the maximum specified in the
ANSI Extended Magnetic Tape Format for Information Interchange 36
Track, Parallel Serpentine proposed specification X3B5/94-043 section
8.2.
4-5 0001h The minimum block length supported is one byte. The minimum block
length indicates the minimum number of bytes that can be read from or
written to the MTU.