9 negotiable field combinations – Seagate Ultra 320 User Manual
Page 62
48
Parallel SCSI Interface Product Manual, Rev. A )
2.12.9
Negotiable field combinations
Not all combinations of the negotiable fields are valid. Only the combinations defined in Table 20 shall be
allowed. All other combinations of the listed fields are reserved.
Table 20:
Valid negotiable field combinations
Transfer
period
factor
REQ/
ACK
offset
Transfer
width
exponent
Protocol options
Description
PCOMP
_
EN
RTI
RD_
STRM
WR_
F
L
O
W
HOLD
_MCS
QAS_REQ
DT_REQ
IU_REQ
Ignore
00h
00h or 01h
0
0
0
0
0
0
0
0
Use ST DATA IN and ST DATA OUT phases
to transfer data with asynchronous transfers.
Ignore
00h
00h or 01h
0
0
0
0
0
1
0
0
Use ST DATA IN and ST DATA OUT phases
to transfer data with asynchronous transfers,
and participate in QAS arbitrations.
0Ah - FFh
01h -
FFh
00h or 01h
0
0
0
0
0
0
0
0
Use ST DATA IN and ST DATA OUT phases
to transfer data with synchronous transfers.
09h - FFh
01h -
FFh
01h
0
0
0
0
0
0
1
0
Use DT DATA IN and DT DATA OUT phases
with data group transfers.
09h - FFh
01h -
FFh
01h
0
0
0
0
0
1
1
0
Use DT DATA IN and DT DATA OUT phases
with data group transfers, and participate in
QAS arbitrations.
0Ah - FFh
01h -
FFh
00h or 01h
0
0
0
0
0
1
0
0
Use ST DATA IN and ST DATA OUT phases
to transfer data with synchronous transfers,
and participate in QAS arbitrations
09h - FFh
01h -
FFh
01h
0
0
0
or
1
0
or
1
0
0
1
1
Use DT DATA IN and DT DATA OUT phases
with synchronous transfers and information
unit transfers
07h
01h-
FFh
01h
0
0
or
1
0
or
1
0
or
1
0
or
1
0
1
1
Use DT DATA IN and DT DATA OUT phases
with paced transfers and information unit
transfers
08h
01h -
FFh
01h
0
or
1
0
or
1
0
or
1
0
or
1
0
or
1
0
1
1
Use DT DATA IN and DT DATA OUT phases
with synchronous transfers and information
unit transfers.
09h - FFh
01h -
FFh
01h
0
0
0
or
1
0
or
1
0
1
1
1
Use DT DATA IN and DT DATA OUT phases
with paced transfers and information unit
transfers, participate in QAS arbitrations, and
issue QAS_REQUEST messages to initiate
QAS arbitrations.
07h
01h-
FFh
01h
0
0
or
1
0
or
1
0
or
1
0
or
1
1
1
1
Use DT DATA IN and DT DATA OUT phases
with paced transfers and information unit
transfers, participate in QAS arbitrations, and
issue QAS_REQUEST messages to initiate
QAS arbitrations
08h
01h -
FFh
01h
0
or
1
0
or
1
0
or
1
0
or
1
0
or
1
1
1
1
Use DT DATA IN and DT DATA OUT phases
with information unit transfers, participate in
QAS arbitrations, and issue QAS_REQUEST
messages to initiate QAS arbitrations.