264 Intel
®
E7520 Memory Controller Hub (MCH) Datasheet
Electrical Characteristics
NOTES:
1. Specified at the measurement point and measured over any 250 consecutive UIs. The test load in Figure 8
17 (not the MCH itself) should be used as the RX device when taking measurements (also refer to the
Receiver Compliance Eye Diagram as shown in Figure 8 19). Refer to document 300312-001 at http://
www.pciexpressdevnet.org/apps/org/workgroup/dgl/document.php?document_id=89 for more information on
the difference between taking pin and pad measurements. If the clocks to the RX and TX are not derived from
the same clock chip the TX UI must be used as a reference for the eye diagram.
2. Impedance during all LTSSM states. When transitioning from a Fundamental Reset to Detect (the initial state
of the LTSSM) there is a 5ms transition time before Receiver termination values must be met on all un-
configured Lanes of a Port.
3. The RX DC Common Mode Impedance that exists when no power is present or Fundamental Reset is
asserted. This helps ensure that the Receiver Detect circuit will not falsely assume a Receiver is powered on
when it is not. This term must be measured at 300mV above the RX ground.
NOTES:
1. These values depend on the HIRCOMP value chosen; the numbers specified here rely on the HIRCOMP
value specified.
Table 6-12. PCI Express Differential Receiver (RX) Input DC Specifications
Symbol Parameter Min Nom Max Unit Notes
Z
RX-DIFF-DC
DC Differential Input Impedance 80 100 120 2
Z
RX-DC
DC Input Common Mode Impedance 40 50 60 1, 2
Z
RX-HIGH-IMP-DC
Powered Down DC Input Common Mode
Impedance
200 k 3
L
RX-SKEW
Total Skew 20 ns
Table 6-13. Hub Interface DC Characteristics
Symbol
Signal
Group
Parameter Min Nom Max Unit Notes
V
IL_HI
(p) Hub Interface Input Low Voltage 0
HIVREF –
0.1
V
V
IH_HI
(p) Hub Interface Input High Voltage
HIVREF +
0.1
0.7 V
V
OL_HI
(p) Hub Interface Output Low Voltage -0.03 0 0.05 V
V
OH_HI
(p) Hub Interface Output High Voltage
HISWNG
– 0.05
HISWNG
HISWNG
+ 0.05
V
I
IL_HI
(p) Hub Interface Input Leakage Current 25 A
C
IN_H
I (p) Hub Interface Input Pin Capacitance 5.0 pF
C
IN
Strobe to Data Pin Capacitance delta – 0.5 0.5 pF
Z
PD
(p) Pull-down Impedance 45 50 55 1
Z
PU
(p) Pull-up Impedance 40 45 50 1
HIVREF (r) Hub Interface Reference Voltage
0.98 x
Nominal
0.236 x
Vcc_MCH
1.02 x
Nominal
2
HISWNG (s)
Hub Interface Swing Reference
Voltage
0.98 x
Nominal
0.536 x
Vcc_MCH
1.02 x
Nominal
2
HIRCOMP (t)
Hub Interface Compensation
Resistance
0.99 x
Nominal
43.2
1.01 x
Nominal