Fujitsu MAS3367 Computer Drive User Manual


 
3.2 Data Access Commands
C141-E167
3 - 73
Also, the size of the range where access is permitted, specified in this command in the "Block count"
field in the CDB, specifies the number of logical data blocks from that starting point. However,
when zero is specified in the "Block count" field, access to the final logical data block of the
specified data space (User Space or CE Space), with the logical data block specified in the "Logical
block address" field as the starting point, is permitted. Figure 3.12 shows the method for
specification of the range where access is permitted in this command.
n+m
n–1 n+m+1
m: Value specified in the "Block count" field
Range where access is permitted by linked commands
nn+3n+2n+1
n: Value specified in the "Logical block address" field
Figure 3.12 SET LIMITS command: Specifying the range where access is permitted
If "1" is specified in bit 1 of CDB byte 1, "RdInh (read inhibit)" flag or in bit 0, "WrInh (write
inhibit) flag, read operations or write operations is prohibited for linked commands following this
command, as shown below.
RdInh WrInh Operation limits
0 0 Read/write operations are permitted in the specified range.
0 1 Read operations only are permitted in the specified range.
1 0 Write operations only are permitted in the specified range.
1 1 Both read and write operations are prohibited. Only access by the SEEK
and SEEK EXTENDED commands is permitted within the specified
range.
When access to logical data blocks outside the address range defined by this command by linked
commands which follow this command is specified, or when a prohibited type of access operation is
specified, that command is terminated with a CHECK CONDITION status without being executed.
(When there is a violation of the (DATA PROTECT [=7] / Write protect [=27-00]: "WrInh" flag, or
when there is a violation of the (DATA PROTECT [=7] / No additional sense information [=00-00]:
"RdInh" flag.) When this command is issued again in a group of commands linked in a series, the
2nd SET LIMITS command is rejected and a CHECK CONDITION status (DATA PROTECT [=7] /
Command sequence error [=2C-00]) is reported.