Pentium® III Processor for the PGA370 Socket at 500 MHz to 866 MHz
3.3.3
Overshoot/Undershoot Pulse Duration
Pulse duration describes the total time an overshoot/undershoot event exceeds the overshoot/
undershoot reference voltage (Vos_ref = 1.635V). 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.
Note: Oscillations below the reference voltage can not be substracted from the total overshoot/
undershoot pulse duration.
Note: Multiple Overshoot/Undershoot events occurring within the same clock cycle must be considered
together as one event. Using the worst case Overshoot/Undershoot Magnitude, sum together the
individual Pulse Duraitons to determine the total Overshoot/Undershoot Pulse Duration for that
total event.
3.3.4
Activity Factor
Activity Factor (AF) describes the frequency of overshoot (or undershoot) occurrence relative to a
clock. Since the highest frequency of assertion of an AGTL+ or a CMOS signal is every other
clock, an AF = 1 indicates that the specific overshoot (or undershoot) waveform occurs EVERY
OTHER clock cycle. Thus, an AF = 0.01 indicates that the specific overshoot (or undershoot)
waveform occurs one time in every 200 clock cycles.
The specifications provided in Table 20 through Table 22 show the Maximum Pulse Duration
allowed for a given Overshoot/Undershoot Magnitude at a specific Activity Factor. Each Table
entry is independent of all others, meaning that the Pulse Duration reflects the existence of
overshoot/undershoot events of that magnitude ONLY. A platform with an overshoot/undershoot
that just meets the pulse duration for a specific magnitude where the AF < 1, means that there can
be NO other overshoot/undershoot events, even of lesser magnitude (note that if AF = 1, then the
event occurs at all times and no other events can occur).
Note: Activity factor for AGTL+ signals is referenced to BCLK frequency.
Note: Activity factor for CMOS signals is referenced to PICCLK frequency.
Datasheet
37
INTEL [ INTEL ]
