Intel AT80604004872AA User Manual
Electrical Specifications
42
Intel® Xeon® Processor 7500 Datasheet, Volume 1
The receiver eye is referenced to V
SS
and all input terminations at the receiver must be
referenced to V
SS
. This input eye must be maintained for the entire duration of the RX
test pattern. An appropriate average transmitter UI must be used as the interval for
measuring the eye diagram. The eye diagram is created using all edges of the RX test
pattern. The eye diagrams shall be measured by observing a continuous pattern at the
pin of the device. Note that the persistent eye diagram is used for determining
conformance to voltage level specifications only.
measuring the eye diagram. The eye diagram is created using all edges of the RX test
pattern. The eye diagrams shall be measured by observing a continuous pattern at the
pin of the device. Note that the persistent eye diagram is used for determining
conformance to voltage level specifications only.
2.5.4.4
Receiver Input Timing
The figure of merit for receiver input timing is the RX eye width, represented by the
symbol T
symbol T
RX-Eye-Min
. The receiver eye width is measured with respect to a delayed
version of the transmitted forwarded clock, as described in
.
2.5.4.5
Summary of Receiver Input Specifications
Figure 2-9. Required Receiver Input Eye (Differential) Showing Minimum Voltage Specs
V
RX-DIFp-p-MIN
V
RX-DIFF
= 0mV
(D+ D- Crossing Point)
V
RX-DIFF
= 0mV
(D+ D- Crossing Point)
Table 2-22. Summary of Differential Receiver Input Specifications (Sheet 1 of 2)
Symbol
Parameter
Min
Max
Units
Comments
V
RX-DIFFp-p
Differential peak-to-peak
input voltage
input voltage
115
1200
mV
V
RX-DIFFp-p
= 2*|V
RX-D+
-
V
RX-D-
|
Measured as:
V
RX-SE
Single-ended voltage (w.r.t. VSS)
on D+/D-
-200
750
mV
V
RX-DIFF-PULSE
Single-pulse peak
differential input voltage
differential input voltage
85
mV
V
RX-DIFF-ADJ-RATIO
Amplitude ratio between
adjacent symbols,
V
adjacent symbols,
V
RX-DIFFp-p
<= 1100 mV
4.0
T
RX-Eye-MIN
Minimum RX Eye Width
0.50
UI
T
RX-DJ-DD
Max RX eye closure due to dual-
dirac deterministic jitter
0.40
UI
T
RX-PW-ZC
Single-pulse width at zero-voltage
crossing
0.55
UI
T
RX-PW-ML
Single-pulse width at minimum-
level crossing
0.2
UI
V
RX-CM-MinEH
Common mode of the input voltage
(V
RX-DIFFp-p
= V
RX-DIFFp-p-min
)
120
310
mV
V
RX-CM
= DC
(avg)
of |V
RX-D+
+ V
RX-D-
|/2