Intel BX80635E52697V2 Manual Do Utilizador

Intel® Xeon® Processor E5-1600 v2/E5-2600 v2 Product Families

155

Datasheet Volume One of Two

 

Overshoot (or undershoot) is the absolute value of the maximum voltage above or 

below V

SS,

 see 

. The overshoot/undershoot specifications limit transitions 

beyond V

CCD

 or V

SS

 due to the fast signal edge rates. The processor can be damaged 

by single and/or repeated overshoot or undershoot events on any input, output, or I/O 

buffer if the charge is large enough (that is, if the over/undershoot is great enough). 
Determining the impact of an overshoot/undershoot condition requires knowledge of 

the magnitude, the pulse direction, and the activity factor (AF). Permanent damage to 

the processor is the likely result of excessive overshoot/undershoot.

Baseboard designs which meet signal integrity and timing requirements and which do 

not exceed the maximum overshoot or undershoot limits listed in 

 will insure 

reliable IO performance for the lifetime of the processor.

1.

These specifications are measured at the processor pad.

2.

Refer to 

 for description of allowable Overshoot/Undershoot magnitude and duration.

3.

TCH is the minimum high pulse width duration.

4.

For PWRGOOD DC specifications see 

.

Overshoot/Undershoot magnitude describes the maximum potential difference between 
a signal and its voltage reference level. For the processor, both overshoot and 

undershoot magnitude are referenced to V

SS

. It is important to note that the overshoot 

and undershoot conditions are separate and their impact must be determined 
independently.

The pulse magnitude and duration, and activity factor must be used to determine if the 

overshoot/undershoot pulse is within specifications.

Overshoot/undershoot pulse duration describes the total amount of time that an 

overshoot/undershoot event exceeds the overshoot/undershoot reference voltage. The 
total time could encompass several oscillations above the reference voltage. Multiple 

overshoot/undershoot pulses within a single overshoot/undershoot event may need to 

be measured to determine the total pulse duration.

Oscillations below the reference voltage cannot be subtracted from the total 

overshoot/undershoot pulse duration.

Activity factor (AF) describes the frequency of overshoot (or undershoot) occurrence 

relative to a clock. Since the highest frequency of assertion of any common clock signal 
is every other clock, an AF = 0.1 indicates that the specific overshoot (or undershoot) 

waveform occurs every other clock cycle.

Intel QuickPath Interconnect

-0.2 * VTT

1.2 * VTT

39 ps

15 ps

1,2

DDR3

-0.2 * V

CCD

1.2 * V

CCD

0.25*T

CH

0.1*T

CH

1,2,3

System Reference Clock (BCLK{0/1})

-0.3V

1.15V

N/A

N/A

1,2

PWRGOOD Signal

-0.420V

VTT + 0.28

N/A

N/A

4