Seagate Cheetah 15K.5 SAS ST373455SS - Manual (Page 70)

64 Cheetah 15K.5 SAS Product Manual, Rev. E
The leading and trailing edge slopes of figure 20 shall be preserved. As a result the amplitude value of Z1 is
less than that given in table 17 and Z1
TOL
and Z1
OP
shall be defined from those slopes by the following equa-
tion:
where:
Z1
TOL
is the value for Z1 to be used for the tolerance masks; and
Z1
OP
, X1
OP
, and X2
OP
are the values in table 17 for Z1, X1, and X2.
The X1 points in the receive tolerance masks are greater than the X1 points in the receive masks, due to the
addition of sinusoidal jitter.
Figure 22 defines the sinusoidal jitter mask.
Figure 22. Sinusoidal jitter mask
Z1
TOL
Z1
OP
x
X2
OP
0 5 ,
( )x
additional sinusoidal jitter
( )
– X1
OP
–
X2
OP
X1
OP
–
----------------------------------------------------------------------------------------------------------------------------------- =
F
NOM
/ 25,000 F
NOM
/ 1,667
Sinusoidal jitter frequency
(log/log plot)
Peak-to-
peak
sinusoidal
jitter
(in UI)
F
NOM
= 1.5 x 10 9 for 1.5 Gbps
F
NOM
= 3.0 x 10 9 for 3.0 Gbps
1.5
0
0.1
Frequency (in kHz)
1.0