Seagate ST973451SS ユーザーズマニュアル
Savvio 15K SAS Product Manual, Rev. B
61
9.5.2.1.3
Jitter tolerance masks
Figure 17 describes the receive tolerance eye masks and is constructed using the X2 and Z2 values given in
table 19. X1
table 19. X1
OP
is half the value for total jitter intable 19 and X1
TOL
is half the value for total jitter in table 20, for
jitter frequencies above ((bit rate) / 1.667).
Figure 17.
Reveive tolerance eye mask
The leading and trailing edge slopes of figure 16 shall be preserved. As a result the amplitude value of Z1 is
less than that given in table 18 and Z1
less than that given in table 18 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 18 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.
addition of sinusoidal jitter.
Absolute
amplitude
(in V)
Z1
TOL
0 V
-Z1
OP
X1
OP
X2
1-X1
TOL
1-X1
OP
Normalized time (in UI)
(additional sinusoidal jitter) / 2
-Z1
TOL
Z1
OP
X1
TOL
Outline of eye mask
after adding
sinusoidal jitter
Outline of eye mask
before adding
sinusoidal jitter
0
1
Z2
-Z2
Z1
TOL
Z1
OP
x
X2
OP
0 5
,
(
)
xadditional sinusoidal jitter
(
)
–
X1
OP
–
X2
OP
X1
OP
–
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