Seagate Ultra 160 - Manual (Page 55)

Parallel SCSI Interface Product Manual, Rev. A ) 41
When negotiating, the responding port shall respond with values that are a subset of the values in the originat-
ing message as indicated in Table 12 (e.g., if the originating message requests a REQ/ACK offset of 10h, the
responding message has a REQ/ACK offset field set to 10h or lower).
Protocol
options
PCOMP_EN Negotiated Sets to 00h Sets to 00h
RTI Negotiated Sets to 00h Sets to 00h
RD_STRM Negotiated Sets to 00h Sets to 00h
WR_FLOW Negotiated Sets to 00h Sets to 00h
HOLD_MCS Negotiated Sets to 00h Sets to 00h
QAS_REQ Negotiated Sets to 00h Sets to 00h
DT_REQ Negotiated Sets to 00h Sets to 00h
IU_REQ
Negotiated Sets to 00h Sets to 00h
Table 12: Responding message requirements
Field Name Message
Response shall be
numerically
Transfer Period Factor
PPR, SDTR Greater than or equal
REQ/ACK Offset PPR, SDTR Less than or equal
Transfer Width Expo-
nent PPR, WDTR 00h or 01h
Protocol
Options
PCOMP_EN PPR Less than or equal
RTI PPR Less than or equal
RD_STRM PPR Less than or equal
WR_FLOW PPR Less than or equal
HOLD_MCS PPR Less than or equal
QAS_REQ PPR Less than or equal
DT_REQ PPR Less than or equal
IU_REQ PPR Less than or equal
Table 11: Negotiable fields and effects of successful negotiation
Field name
Negotiation message pair
PPR WDTR SDTR