mpc8640 Freescale Semiconductor, Inc, mpc8640 Datasheet - Page 71

• Manufacturer Part Number: mpc8640
• Description: Integrated Host Processor
• Manufacturer: Freescale Semiconductor, Inc

14.4.2
The Tx eye diagram in
Figure
There are two eye diagrams that must be met for the transmitter. Both eye diagrams must be aligned in
time using the jitter median to locate the center of the eye diagram. The different eye diagrams will differ
in voltage depending whether it is a transition bit or a de-emphasized bit. The exact reduced voltage level
of the de-emphasized bit will always be relative to the transition bit.
The eye diagram must be valid for any 250 consecutive UIs.
A recovered Tx UI is calculated over 3500 consecutive unit intervals of sample data. The eye diagram is
created using all edges of the 250 consecutive UI in the center of the 3500 UI used for calculating the TX
UI.
Freescale Semiconductor
52) in place of any real PCI Express interconnect + Rx component.
Figure 50. Minimum Transmitter Timing and Voltage Output Compliance Specifications
Transmitter Compliance Eye Diagrams
MPC8640 and MPC8640D Integrated Host Processor Hardware Specifications, Rev. 3
It is recommended that the recovered Tx UI is calculated using all edges in
the 3500 consecutive UI interval with a fit algorithm using a minimization
merit function (that is, least squares and median deviation fits).
Figure 50
is specified using the passive compliance/test measurement load (see
NOTE
PCI Express
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