Seagate ST9900705SS Savvio 10K.2 SAS Product Manual - Page 68

9.5.2.1.2 Receive eye mask Figure 15 describes the receive eye mask. This eye mask applies to jitter after the 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). Absolute amplitude (in V) Z2 Z1 0 V -Z1 -Z2 0 X1 X2 1-X1 1 1-X2 Normalized time (in UI) Figure 15. Receive eye mask Verifying compliance with the limits represented by the receive eye mask should be done with reverse channel traffic present in order that the effects of crosstalk are taken into account. 9.5.2.1.3 Jitter tolerance masks Figure 16 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 (in V) (additional sinusoidal jitter) / 2 Z2 Z1OP Z1TOL 0 V -Z1TOL -Z1OP -Z2 0 X1OP X2 1 1-X1OP X1TOL 1-X1TOL Normalized time (in UI) Outline of eye mask before adding sinusoidal jitter Outline of eye mask after adding sinusoidal jitter Figure 16. Reveive tolerance eye mask 62 Savvio 10K.2 SAS Product Manual, Rev. D