Seagate Cheetah 15K.6 SAS Product Manual page 75

9.5.2.3.2 Receiver jitter tolerance
Table 19 defines the amount of jitter the receiver shall tolerate .
Table 19: Receiver jitter tolerance
1.5 Gbps
Sinusoidal Deterministic
b,c
jitter
0.10
a Units are in UI.
b The jitter values given are normative for a combination of deterministic jitter, random jitter, and sinusoidal jitter that
receivers shall be able to tolerate without exceeding a BER of 10
progressively greater amplitude at lower frequencies, according to the mask in figure 19 with the same deterministic
jitter and random jitter levels as were used in the high frequency sweep.
c Sinusoidal swept frequency: 900 kHz to > 5 MHz.
d Sinusoidal swept frequency: 1.800 kHz to > 5 MHz.
e No value is given for random jitter. For compliance with this standard, the actual random jitter amplitude shall be the
value that brings total jitter to the stated value at a probability of 10
added to ensure the receiver has sufficient operating margin in the presence of external interference.
f Deterministic jitter: 900 kHz to 750 MHz.
g Deterministic jitter: 1.800 kHz to 1.500 MHz.
h The deterministic and total values in this table apply to jitter after application of a single pole high-pass frequency-
weighting function that progressively attenuates jitter at 20 dB/decade below a frequency of ((bit rate) / 1.667).
9.5.2.3.3 Compliant jitter test pattern (CJTPAT)
The CJTPAT within a compliant protocol frame is used for all jitter testing unless otherwise specified. See the
SAS Interface Manual for definition of the required pattern on the physical link and information regarding spe-
cial considerations for scrambling and running disparity.
9.5.2.3.4 Impedance specifications
Table 20 defines impedance requirements.
Table 20: Impedance requirements (Sheet 1 of 2)
Requirement
Time domain reflectometer rise time 20 % to 80 %
Media (PCB or cable)
b,c,d
Differential impedance
Differential impedance imbalance
Common mode impedance
Mated connectors
b,c,d
Differential impedance
Differential impedance imbalance
Common mode impedance
Receiver termination
b,e,f
Differential impedance
Differential impedance imbalance
Receiver termination time constant
Cheetah 15K.6 SAS Product Manual, Rev. A
a
Total
e,f,h h
jitter jitter
0.35 0.65
b,c,d,g
b,c,d
b,c,d,g
b,c,d
b,e,f,g
b,e,f
Sinusoidal
b,d
jitter
0.10
-12
. Receivers shall tolerate sinusoidal jitter of
-12
. The additional 0.1 UI of sinusoidal jitter is
Units 1.5 Gbps
a,b
ps 100
ohm 100 ± 10
ohm 5
ohm 32.5 ± 7.5
ohm 100 ± 15
ohm 5
ohm 32.5 ± 7.5
ohm 100 ± 15
ohm 5
ps 150 max
a
3.0 Gbps
Deterministic Total
e,g,h
jitter jitter
0.35 0.65
3.0 Gbps
50
100 ± 10
5
32.5 ± 7.5
100 ± 15
5
32.5 ± 7.5
100 ± 15
5
100 max
h
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