Seagate ST9900805SS Savvio 10K.1 SAS Product Manual - Page 77

Receiver characteristics

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Figure 25 shows an ISI loss example at 1.5 Gbps. S21 (dB) 0 Compliance interconnect magnitude response and ISI loss example for 1.5 Gbps ISI loss > 2.0 dB -5.4 dB Sample compliance interconnect 0.15 0.75 1.5 Frequency (GHz) Figure 25. ISI loss example at 1.5 Gbps 9.5.2.5 Receiver characteristics The drive receiver is A.C. coupled. The receive network terminates the TxRx connection by a 100 ohm equivalent impedance as specified in table 31. The receiver operates within a BER of 10-12 when a SAS signal with valid voltage and timing characteristics is delivered to the compliance point from a 100 ohm source. The received SAS signal are considered valid if it meets the voltage and timing limits specified in table 28. Additionally the receiver operates within the BER objective when the signal at a receiving phy has the additional sinusoidal jitter present that is specified in table 30 and the common mode signal VCM over frequency range FCM as specified in table 26. The jitter tolerance is shown in Figure 21 for all Rx compliance points in a TxRx connection. The figure given assumes that any external interference occurs prior to the point at which the test is applied. When testing the jitter tolerance capability of a receiver, the additional 0.1 UI of sinusoidal jitter may be reduced by an amount proportional to the actual externally induced interference between the application point of the test and the input to the receiving phy. The additional jitter reduces the eye opening in both voltage and time. Savvio SAS Product Manual, Rev. D 71

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Savvio SAS Product Manual, Rev. D
71
Figure 25 shows an ISI loss example at 1.5 Gbps.
Figure 25.
ISI loss example at 1.5 Gbps
9.5.2.5
Receiver characteristics
The drive receiver is A.C. coupled. The receive network terminates the TxRx connection by a 100 ohm equiva-
lent impedance as specified in table 31.
The receiver operates within a BER of 10
-12
when a SAS signal with valid voltage and timing characteristics is
delivered to the compliance point from a 100 ohm source. The received SAS signal are considered valid if it
meets the voltage and timing limits specified in table 28.
Additionally the receiver operates within the BER objective when the signal at a receiving phy has the addi-
tional sinusoidal jitter present that is specified in table 30 and the common mode signal V
CM
over frequency
range F
CM
as specified in table 26. The jitter tolerance is shown in Figure 21 for all Rx compliance points in a
TxRx connection. The figure given assumes that any external interference occurs prior to the point at which the
test is applied. When testing the jitter tolerance capability of a receiver, the additional 0.1 UI of sinusoidal jitter
may be reduced by an amount proportional to the actual externally induced interference between the applica-
tion point of the test and the input to the receiving phy. The additional jitter reduces the eye opening in both
voltage and time.
ISI loss
> 2.0 dB
Frequency (GHz)
Sample compliance interconnect
0
1.5
0.75
0.15
S
21
(dB)
Compliance interconnect magnitude response and ISI
loss example for 1.5 Gbps
-5.4 dB