Pre-Fetch (34H) - HP 2600fx - Optical Disk Drive Command Reference Manual

Table 2-81
SCSI-2 Drive Command Set

Pre-Fetch (34H)

Pre-Fetch (34H)
The Pre-Fetch command is used to transfer the specified number of data
blocks starting from the specified logical block address to cache memory.
Pre-Fetch Command
Byte 7 6
0
1
2
3
4
5
6
7
8
9
Immed An Immediate bit of 1 indicates that the drive returns a
status as soon as the command descriptor block is
validated.
An Immed bit of 0 indicates that the status is not
returned until the operation is completed.
Transfer
Length This field indicates the number of contiguous logical
blocks of data to be transferred.
Rel Adr A relative address bit of one indicates that logical block
address specified is a two's complement offset from the
last logical block address accessed.
A value of 0 indicates that the logical block address is an
absolute address.
2-94
5 4 3
Operation Code (34H)
Reserved (0)
Logical Block Address (MSByte)
Logical Block Address
Logical Block Address
Logical Block Address (LSByte)
Reserved (0)
Transfer Length (MSByte)
Transfer Length (LSByte)
Reserved (0)
2 1 0
Immed RelAdr
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Chapter 2