Seagate Ultra 160 User Manual
Page 38
24
Parallel SCSI Interface Product Manual, Rev. A )
Table 8:
Receive SCSI bus data and information phase DT timing values
[1]
SCSI bus timing values specified by the maximum transfer rate for the given range shall apply even if a
slower transfer rate within the given range is negotiated.
[2]
See Section 2.6 for measurement points for the timing specifications.
[3]
See Section 9.6 in the ANSI SCSI Parallel Interface-5 (SPI-5) specification for examples of how to calcu-
late setup and hold timing.
[4]
Calculated assuming timing budget shown in Table 9.
Note.
Fast-160 and fast 320 SCSI devices shall not change timing parameters between training or reset
events.
Timing description
Reference
Type
Timing values for negotiated transfer rate in nanoseconds
unless otherwise noted
Fast-10
Fast-20
Fast-40
Fast-80
Fast-
160
Fast-
320
ATN receive setup time
min
13.6
7.8
4.9
3.45
3.0
3.0
Flow control receive hold time
min
11.6
5.8
2.9
1.45
3.0
3.0
Flow control receive setup time
min
18.6
12.8
9.9
8.45
3.0
3.0
pCRC receive hold time
min
11.6
5.8
2.9
1.45
N/A
N/A
pCRC receive setup time
min
18.6
12.8
9.9
8.45
N/A
N/A
Receive assertion period
min
80
40
20
8.5
4.74
1.615
Receive hold time
min
11.6
5.8
2.9
1.45
-0.08
-6.635
Receive negation period
min
80
40
20
8.5
4.74
1.615
Receive setup time
min
11.6
5.8
2.9
1.45
-6.33
-9.76
Receive REQ(ACK) period toler-
ance
min
0.7
0.7
0.7
0.7
0.06
0.06
Receive REQ assertion period
with P_CRCA transitioning
min
85.5
48
32.5
21
N/A
N/A
Receive REQ negation period
with P_CRCA transitioning
min
85.5
48
32.5
21
N/A
N/A
Receive skew compensation
max
N/A
N/A
N/A
N/A
N/A
N/A
Receive internal hold time
min
N/A
N/A
N/A
N/A
0.345
0.032
Receive internal setup time
min
N/A
N/A
N/A
N/A
0.345
0.032
Receiver de-skewed data valid
window
min
N/A
N/A
N/A
N/A
±
2.1
±
1.1