Electrical Specifications
Table 2-13. Parameter Values for Intel QPI Channel at 4.8 GT/s (Sheet 2 of 2)
Symbol
Parameter
Min
-1
Nom
Max
Unit
Notes
T
Delay of any data lane relative to
the clock lane, as measured at
the end of Tx+ channel. This
parameter is a collective sum of
effects of data clock mismatches
in Tx and on the medium
3
UI
Rx-data-clk-skew-pin
connecting Tx and Rx.
VRx-CLK
Forward CLK Rx input voltage
sensitivity (differential pp)
180
350
mV
mV
V
V
DC common mode ranges at the
Rx input for any data or clock
channel
125
-50
Rx-cm-dc-pin
Rx-cm-ac-pin
AC common mode ranges at the
Rx input for any data or clock
channel, defined as:
50
mV
2
((V
+ V /2 - V
)
RX-cm-dc-pin
D+
D-
Notes:
1.
1300mVpp swing is recommended when CPU to CPU length is within 2” of PDG max trace length. Note that
default value is 1100mVpp.
Measure AC CM noise at the TX and decimate to its spectral components. For all spectral components above
3.2GHz, apply the attenuation of the channel at the appropriate frequency. If the resultant AC CM at the
receiver is met after taking out the appropriate spectral components meets the RX AC CM spec then we can
allow the transmitter AC CM noise to pass.
2.
3.
Measured with victim lane running clock pattern, neighboring aggressor lanes running DC pattern and far
aggressor lanes running PRBS pattern.
Table 2-14. Parameter Values for Intel QPI at 6.4 GT/s (Sheet 1 of 2)
Symbol
Parameter
Min
800
Nom
Max
1500
Unit
Notes
V
Z
Transmitter differential swing
mV
1
Tx-diff-pp-pin
DC resistance of Tx terminations
at half the single ended swing
38
47
Ω
TX_LOW_CM_DC
RX_LOW_CM_DC
(which is usually 0.25*V
Tx-diff-pp-
) bias point
pin
Z
DC resistance of Rx terminations
at half the single ended swing
38
47
Ω
(which is usually 0.25*V
pin
Tx-diff-pp-
) bias point
V
V
Transmitter output DC common
mode, defined as average of V
0.23
0.27
Fraction of
Tx-diff-pp-pin
4
2
Tx-cm-dc-pin
V
D+
and V
D-
Transmitter output AC common
mode, defined as ((V + V )/2 -
-0.065
0.065
Fraction of
Tx-cm-ac-pin
V
D+
D-
Tx-diff-pp-pin
V
)
Tx-cm-dc-pin
TX
TX
TX
TX
Average of absolute UI-UI jitter
-
0.0325
0.12
UI
UI
UI
UI
duty-pin
0.0325
UI-UI jitter measured at Tx output -0.12
pins with 1E-7 probability.
3
jitUI-UI-1E-7-pin
jitUI-UI-1E-9-pin
clk-acc-jit-N_UI-1E-7
UI-UI jitter measured at Tx output -0.137
pins with 1E-9 probability.
0.137
0.2
p-p accumulated jitter out of
transmitter over 0 <= n <= N UI
where N=12, measured with 1E-7
probability.
0
0
TX
p-p accumulated jitter out of
transmitter over 0 <= n <= N UI
where N=12, measured with 1E-9
probability.
0.23
UI
clk-acc-jit-N_UI-1E-9
Datasheet Volume 1 of 2
33
INTEL [ INTEL ]
