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Table 1.16
Timing description
1
ATN Transmit Setup Time
2
ATN Receive Setup Time
3
Cable Skew (3)
4
Receive Assertion Period (4)
5
Receive Hold Time (4)
6
Receive Negation Period (4)
7
Receive Setup Time (4)
8
Receive REQ (ACK) Period Tolerance
9
Signal Timing Skew
10
REQ (ACK) Period
11
Transmit Assertion Period (4)
12
Transmit Hold Time (4)
13
Transmit Negation Period (4)
14
Transmit Setup Time (4)
15
Transmit REQ (ACK) Period Tolerance
Note:
(3) Cable Skew is measured at each device connection with the transmitted skew subtracted from
the received skew. (4) See Fig.1-17,18,19 for measurement points for the timing specifications. (5)
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.
Table 1.17
Timing description
1
Cable skew(6)
2
REQ(ACK) period
3
Residual Skew Error(8)
4
De-skewed data valid window(9)
5
Skew correction range(9)
6
Signal timing skew
7
Strobe Offset Tolerance
Fast-160 SCSI devices shall not change timing parameters between training or reset events.
Note:
(6)Cable skew is measured at each SCSI device connection within the same bus segment with the
transmitted skew subtracted from the received skew. (7) 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. (8) Calculated assuming timing budget shown in table 46. (9) Measured
at the receiver terminal using clean input signals with 500 mV peak amplitude and 1 ns rise and fall
time between 20 % and 80 % of the signal. (10) Relative to the REQ(ACK) clocking signal.
C141-C011
SCSI bus data & information phase ST timing values
Miscellaneous SCSI bus data & information phase DT timing values
Type
Async
Fast-5
min.
90
33
min.
45
17
max.
4
4
min.
N/A
70
min.
N/A
25
min.
N/A
70
min.
N/A
15
min.
N/A
1.1
max.
8
8
min.
N/A
200
min.
N/A
80
min.
N/A
53
min.
N/A
80
min.
N/A
23
max.
N/A
1
Type
Fast-10
Fast-20
Max
4
Nominal
200
100
Max
N/A
N/A
Min
N/A
N/A
Min
N/A
N/A
Max
26.8
13.4
Max
N/A
N/A
Timing values [ns] (5)
Fast-10
Fast-20
33
21.5
17
8.5
4
3
22
11
25
11.5
22
11
15
6.5
1.1
1.1
8
5
100
50
30
15
33
16.5
30
15
23
11.5
1
1
Timing values [ns] (7)
Fast-40
Fast-80
3
2.5
2.5
50
25
N/A
N/A
N/A
N/A
N/A
N/A
6.7
3.35
N/A
N/A
1-29
Fast-40
19.25
6.75
2.5
6.5
4.75
6.5
4.75
1.1
4.5
25
8
9.25
8
9.25
1
Fast-160
2.5
12.5
±0.15
±2.1
±3.65(10)
4.85
±0.125
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