Intel Itanium 9140M NE80567KF028009 Manual De Usuario

23

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

CTERM

 voltage (or below GND), as shown in 

. The overshoot/

undershoot specifications limit transitions beyond V

CTERM

 or GND due to the fast signal 

edge rates. The processor can be permanently damaged by repeated overshoot or 
undershoot events on any input, output, or I/O buffer if the charge is large enough 
(that is, if the overshoot/undershoot is great enough). Determining the impact of an 
overshoot/undershoot condition requires knowledge of the magnitude, the pulse 
duration, and the activity factor (AF). 

Magnitude describes the maximum potential difference between a signal and its voltage 
reference level. For the processor, both are referenced to GND, as shown in 

. 

It is important to note that overshoot and undershoot conditions are separate and their 
impact must be determined independently. Overshoot/undershoot magnitude levels 
must observe the absolute maximum specifications listed in 

 

through 

. These specifications must not be violated at any time, regardless of bus 

activity or system state. Within these specifications are threshold levels that define 
different allowed pulse duration. Provided that the magnitude of the overshoot/
undershoot is within the absolute maximum specifications, the pulse magnitude, 
duration, and activity factors must all be used to determine if the overshoot/
undershoot pulse is within specifications.

000588

V

CTERM

Maximum

Absolute

Overshoot

Maximum

Absolute

Undershoot

Time-dependent
Overshoot

Time-dependent
Undershoot

V

REF

V

OL

GND

V

MIN

V

MAX