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21020285 D User’s Guide
Chapter 5 Initiator Mode Pass-through Commands
Page 5 - 4 Initiator Pass-through Parameter Block Format
Flags-1
The Flags-1 byte controls the command operation. Its bits have these meanings:
Note
Bits 7, 2 and 1 work
intra-dependently. They
are automatically set by
the adapter to specific
values for standard SCSI
and SCSI-2 command.
Their values are
described in Table 25 on
page 5 - 3.
DIR Direction of Data Transfer - Both the DBV and the DAT bits must be
set to 1 for this bit to have meaning for an RF3880 operation. Otherwise its
value is ignored.
0 ⇒ Data transfer is from the target.
1 ⇒ Data transfer is to the target.
DAT Data Transfer - This bit is available to be used to enhance efficiency
of vendor-unique commands. (It is automatically set for standard commands.)
If the command you are issuing is vendor-unique, this bit informs the adapter
that a data-in or data-out phase will occur during the command.
0 ⇒ Command has no data phase.
1 ⇒ Data phase will occur.
IRS Inhibit Request Sense - Selects whether Sense Data is to be gathered
automatically by the adapter (in response to a Check Condition status from a
device) or given to the host to do so.
0 ⇒ Automatic Request Sense issued to device reporting Check Condition.
1 ⇒ Check Condition status of device reported to Host. Host must request the
device status.
ICC Inhibit Command Complete Interrupt - Inhibits the interrupt that
notifies the host of command completion. By inhibiting interrupts for a number
of commands and then enabling an interrupt for one, you can reduce the number
of interrupts to service.
0 ⇒ Interrupts enabled for this command.
1 ⇒ Interrupts inhibited for this command.
DBV Data Bits Valid - Use this bit when you wish to override the default
values of the DAT and DIR bits to implement vendor-unique commands or
alter those automatically set for standard SCSI as shown in Table 25 on page
5 - 3.
0 ⇒ Normal operation.
1 ⇒ DIR and DAT values in the Flag byte are valid and override the defaults.
BITS
76543210
DBV 0 ICC 0 IRS DAT DIR 0
Table 27: Bit-meanings of Flags-1 Field