Product manual

3.4.6 Read (6) command (08
H
)
When the drive receives the Read command, it transfers data to the
initiator.
The Read-Write Error Recovery page (01
H
) determines how the drive
handles errors during a Read command. The Read-Write Error Recovery
page is discussed in Appendix C.1 on page 98.
If there is a reservation access conflict, this command terminates with a
reservation conflict status and no data is read. For more information
about the reservation conflict status, see Section 3.2. on page 35.
In systems that support disconnection, the drive disconnects when a valid
Read command is received, unless the data is available in the cache
buffer. The buffer-full ratio byte of the Disconnect/Reconnect page
determines when the drive reconnects. (The Disconnect/Reconnect
page is discussed in Section C.2. on page 100). The drive may discon-
nect, if allowed, whenever there is less than one block in the buffer.
Because the drive uses read look-ahead functions, it may read more
data into the buffer than specified by the transfer length in the CDB.
Note.
The Read (6) command cannot access all logical blocks on the
drive. The Read (10) command must be used to access all logical
blocks.
Bytes
Bits
76543210
000001000
1 LUN Logical block address (MSB)
2 Logical block address
3 Logical block address (LSB)
4 Transfer length
500000000
Bytes 1–3
The
logical block address
specifies the logical block where
the read begins.
Byte 4
The
transfer length
specifies the number of contiguous
logical blocks of data to be transferred. A transfer length
of 0 indicates that 256 logical blocks will be transferred. Any
other value indicates the number of logical blocks trans-
ferred.
Medalist Pro 2160N/2160WC Product Manual, Rev. A 45