Datasheet

Intel® Xeon™ Processor with 512 KB L2 Cache
52 Datasheet
3.3.6 Determining if a System Meets the Overshoot/Undershoot
Specifications
The overshoot/undershoot specifications listed in the following tables specify the allowable
overshoot/undershoot for a single overshoot/undershoot event. However most systems will have
multiple overshoot and/or undershoot events that each have their own set of parameters (duration,
AF and magnitude). While each overshoot on its own may meet the overshoot specification, when
the total impact of all overshoot events are considered, the system may fail. A guideline to ensure a
system passes the overshoot and undershoot specifications is shown below:
• Ensure that no signal ever exceeds V
CC
or -0.25 V OR
• If only one overshoot/undershoot event magnitude occurs, ensure it meets the overshoot/
undershoot specifications in the following tables OR
• If multiple overshoots and/or multiple undershoots occur, measure the worst case pulse
duration for each magnitude and compare the results against the AF = 1 specifications. If all of
these worst case overshoot or undershoot events meet the specifications (measured time <
specifications) in the table (where AF=1), then the system passes.
The following notes apply to Table 24 through Table 27:
• Absolute Maximum Overshoot magnitude of 1.8V must never be exceeded.
• Absolute Maximum Overshoot is measured referenced to V
SS
, Pulse Duration of overshoot is
measured relative to V
CC
.
• Absolute Maximum Undershoot and Pulse Duration of undershoot is measured relative to V
SS
.
• Ringback below V
CC
cannot be subtracted from overshoots/undershoots.
• Lesser undershoot does not allocate longer or larger overshoot.
• System designers are strongly encouraged to follow Intel’s layout guidelines.
• All values specified by design characterization.