Seagate Ultra 160 - Manual (Page 94)

80 Parallel SCSI Interface Product Manual, Rev. A
3.11.4 Phase sequences for physical reconnection or selection without using attention condition
with information unit transfers enabled
The sequences for physical reconnection or selection without using attention condition while an information
unit transfer agreement is in effect shall be as shown in Figure 13.
The normal progression for selection without using attention condition (see Section 3.2.1.1.3) if QAS is dis-
abled is:
1. from the BUS FREE phase to ARBITRATION;
2. from ARBITRATION to SELECTION or RESELECTION;
3. from SELECTION or RESELECTION to one or more DT DATA phases; and
4. from the final DT DATA phase to BUS FREE.
[1] See figures 15, 16, 17, and 18 for the sequencing of SPI units within the DT DATA phases.
Figure 13. Phase sequences for physical reconnection or selection without using attention condition/ with
information unit transfers enabled
DT DATA [1]
MESSAGE OUT
MESSAGE IN
ARBITRATION
BUS FREE
RESELECTION
Hard reset
or protocol
error
SELECTION