PCI Express
Table 62. Differential Receiver (RX) Input Specifications (continued)
Symbol
Parameter
Min Nominal
Max
Units
Comments
T
Maximum time
between the jitter
median and
maximum
deviation from
the median.
—
—
0.3
UI
Jitter is defined as the measurement
variation of the crossing points (V
RX-EYE-MEDIAN-to-MAX
-JITTER
RX-DIFFp-p
= 0 V) in relation to a recovered TX UI. A
recovered TX UI is calculated over 3500
consecutive unit intervals of sample data.
Jitter is measured using all edges of the
250 consecutive UI in the center of the 3500
UI used for calculating the TX UI. See
Notes 2, 3 and 7.
V
AC Peak
Common Mode
Input Voltage
—
15
6
—
—
—
150
—
mV
dB
dB
V
V
V
= |V
+V
|/2 -
RXD-
RX-CM-ACp
RX-CM-ACp
RX-CM-DC
RXD+
(avg)
= DC
of |V
+ V
|/2
RX-D-
RX-CM-DC
RX-D+
See Note 2
RL
Differential
Return Loss
Measured over 50 MHz to 1.25 GHz with
the D+ and D- lines biased at +300 mV and
-300 mV, respectively.
RX-DIFF
See Note 4
RL
Z
Common Mode
Return Loss
—
Measured over 50 MHz to 1.25 GHz with
the D+ and D- lines biased at 0 V. See Note
4
RX-CM
DC Differential
Input Impedance
80
40
100
50
120
60
Ω
Ω
RX DC Differential mode impedance. See
Note 5
RX-DIFF-DC
Z
Z
DC Input
Impedance
Required RX D+ as well as D- DC
Impedance (50 ± 20% tolerance). See
Notes 2 and 5.
RX-DC
Powered Down
DC Input
Impedance
200 k
65
—
—
—
—
175
10
Ω
Required RX D+ as well as D- DC
Impedance when the Receiver terminations
do not have power. See Note 6.
RX-HIGH-IMP-DC
V
Electrical Idle
Detect Threshold
mV
ms
V
= 2*|V
-V
RX-D-
|
RX-IDLE-DET-DIFFp-p
RX-IDLE-DET-DIFFp-p
RX-D+
Measured at the package pins of the
Receiver
T
Unexpected
Electrical Idle
Enter Detect
Threshold
—
An unexpected Electrical Idle (V
V
no longer than T
to signal an unexpected idle condition.
<
RX-DIFFp-p
RX-IDLE-DET-DIFF-
) must be recognized
ENTERTIME
RX-IDLE-DET-DIFFp-p
RX-IDLE-DET-DIFF-ENTERING
Integration Time
MPC8572E PowerQUICC III Integrated Processor Hardware Specifications, Rev. 4
Freescale Semiconductor
87
FREESCALE [ Freescale ]
