Seagate ST936701SS, ST973401SS manual Jitter tolerance masks, Reveive tolerance eye mask

9.5.2.1.3Jitter tolerance masks

Figure 20 describes the receive tolerance eye masks and is constructed using the X2 and Z2 values given in

table 29. X1OP is half the value for total jitter intable 29 and X1TOL is half the value for total jitter in table 30, for jitter frequencies above ((bit rate) / 1.667).

Absolute
amplitude			(additional sinusoidal jitter) / 2
(in V)
Z2
Z1OP
Z1TOL
0 V			Outline of eye mask
			before adding
-Z1TOL			sinusoidal jitter
-Z1OP
-Z2			Outline of eye mask
			after adding
			sinusoidal jitter
0	X1OP	X2	1
			1-X1OP
	X1TOL		1-X1TOL

Normalized time (in UI)

Figure 20. Reveive tolerance eye mask

The leading and trailing edge slopes of figure 19 shall be preserved. As a result the amplitude value of Z1 is

less than that given in table 28 and Z1TOL and Z1OP shall be defined from those slopes by the following equa-
tion:	X2OP – ((0, 5)xadditional sinusoidal jitter) – X1OP
Z1TOL
	= Z1OPx-----------------------------------------------------------------------------------------------------------------------------------
	X2OP – X1OP

where:

Z1TOL is the value for Z1 to be used for the tolerance masks; and

Z1OP, X1OP, and X2OP are the values in table 28 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.

Savvio SAS Product Manual, Rev. D 63