Valid Protocol Options Bit Combinations - Fujitsu MAN3184 SERIES Specifications

An information units enable request bit (IU_REQ) of zero indicates that information unit transfers
shall not be used (i.e., data group transfers shall be enabled) when received from the originating
SCSI device and that information unit transfers are not supported when received from the
responding SCSI device. An IU_REQ bit of one indicates that information unit transfers shall be
used when received from the originating SCSI device and that information unit transfers are
supported when received from the responding SCSI device. If the IU_REQ bit is changed from the
previous agreement (i.e., zero to one or one to zero) as a result of a negotiation the TARG shall go
to a BUS FREE phase on completion of the negotiation.
Note:
MAN3xxxMx is not support an information units enable request bit (IU_REQ).
A DT enable request bit (DT_REQ) of zero indicates that DT DATA phases are to be disabled
when received from the originating SCSI device and that DT DATA phases are not supported
when received from the responding SCSI device. An DT_REQ bit of one indicates that DT DATA
phases are to be enabled when received from the originating SCSI device and that DT DATA
phases are supported when received from the responding SCSI device.
A QAS enable request bit (QAS_REQ) of zero indicates that QAS is to be disabled when received
from the originating SCSI device and that QAS is not supported when received from the
responding SCSI device.
Note:
MAN3xxxMx does not support a QAS enable request bit (QAS_REQ).
Not all combinations of the protocol options bits are valid. Only the bit combinations defined in
table 2.11 shall be allowed all allowed. All other combinations are reserved.
QAS_REQ
0
0
0
1
2 - 30
Table 2.11

Valid protocol options bit combinations

DT_REQ IU_REQ
0 0
1 0
1 1
1 1
C141-E123-01EN
DESCRIPTION
Use ST DATA IN and ST DATA OUT phases
to transfer data
Use DT DATA IN and DT DATA OUT phases
with data group transfers
not Support
not Support