User`s manual

siop_struc (Command Structure)
SBCSCSI/D1 B-7
B
Bit 10 -- SIOPADD
config mode
If set, the Firmware sets the SCSI address at which the SIOP resides. The user
designates the address in the device address field of the command structure.
Bit 9 -- SIOPINT
config mode
If set, the Firmware installs the interrupt level at which the SIOP Firmware
interrupts the MVME167/MVME187 MPU. The user designates the interrupt
level in the SIOP interrupt level field of the command structure.
Bit 8 -- SCSIRST
config mode
If set, the Firmware causes the SCSI bus to be reset and terminated status is
returned for all pending commands. For all LUNs, internal synchronous data
rate information is set to asynchronous and internal tagged command queuing
information is set to non-support.
Bit 7 -- TAG_Q
config mode
If set, the user is informing the initiator mode Firmware that the drive defined
by the device address field and the LUN field has been enabled or disabled for
SCSI tagged command queuing. If enabled the user specifies with a non-zero
value the maximum number of commands the target LUN can queue in the
queue depth field of the command structure. The Firmware handles the
message exchanges that are required for tagged command queuing. The
simple queue tag message is the tagged queuing message the Firmware uses. If
the FIRST bit is set then the Firmware uses the head of queue tag message. The
initiator mode Firmware keeps track of the tags and makes status available to
the user as soon as commands are completed by the target. The user must
insure that the target LUN is in the tagged command queuing mode before
sending this configuration request to the Firmware.
If tagged command queuing has been enabled and the user disables tagged
command queuing then the user must notify the Firmware. This notification
is done by placing a value of zero (0) in the queue depth field for a TAG_Q
configuration mode request. However, all outstanding tagged commands
must be completed before disabling tagged command queuing.