Electrical Specifications
2.5.1
Intel QPI Signaling Specifications
Intel QPI electrical specifications call out specifications that are common across all
platforms and specifications that target Intel QPI within Enterprise MP class server
systems.
2.5.1.1
Intel QPI Reference Clocking Specifications
Reference clock requirements required by the PLL as measured at the package pin.
Table 2-9 provides a list of system clock specifications.
Figure 2-5. Validation Topology for Testing Specifications of the Reference Clock
Figure 2-6. Differential Waveform Measurement Points
Table 2-9.
System Clock Specifications (Sheet 1 of 2)
Symbol
Parameter
Min
Nom
Max
Unit
MHz
Notes
f
System clock frequency
133.33
Refclk
ER
ER
Rise and fall slope
parameter
1.0
4.0
V/nsec
Refclk-diffRise,
Refclk-diffFall
V
V
V
Single ended maximum
voltage with overshoot
1150
mV
mV
mV
Refclk-max
Refclk-min
Cross
Single ended minimum
voltage with overshoot
-350
250
Absolute crossing point
limits between Refclk+ and
Refclk- waveforms
550
140
See
Figure 2-6
V
V
Peak-peak variation in
crossing points
See
Figure 2-6
Cross_delta
High of the differential
150
mV
Refclk_diff-ih
voltage (V
+ - V
-)
Refclk
Refclk
above zero
Datasheet Volume 1 of 2
27
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