Dual-Core Intel® Xeon® Processor 3000 Series Datasheet 33
Electrical Specifications
2.8 PECI DC Specifications
PECI is an Intel proprietary one-wire interface that provides a communication channel
between Intel processors (may also include chipset components in the future) and
external thermal monitoring devices. The processor contains Digital Thermal Sensors
(DTS) distributed throughout die. These sensors are implemented as analog-to-digital
converters calibrated at the factory for reasonable accuracy to provide a digital
representation of relative processor temperature. PECI provides an interface to relay
the highest DTS temperature within a die to external management devices for
thermal/fan speed control. More detailed information is available in the Platform
Environment Control Interface (PECI) Specification.
Notes:
1. Unless otherwise noted, all specifications in this table apply to all processor frequencies.
2. Crossing voltage is defined as the instantaneous voltage value when the rising edge of BCLK0 equals the falling edge of BCLK1.
3. The crossing point must meet the absolute and relative crossing point specifications simultaneously.
4. V
Havg
is the statistical average of the V
H
measured by the oscilloscope.
5. V
Havg
can be measured directly using “Vtop” on Agilent* oscilloscopes and “High” on Tektronix* oscilloscopes.
6. Overshoot is defined as the absolute value of the maximum voltage.
7. Undershoot is defined as the absolute value of the minimum voltage.
8. Ringback Margin is defined as the absolute voltage difference between the maximum Rising Edge Ringback and the maximum
Falling Edge Ringback.
9. Threshold Region is defined as a region entered around the crossing point voltage in which the differential receiver switches. It
includes input threshold hysteresis.
Figure 2-7. Differential Clock Crosspoint Specification
660 670 680 690 700 710 720 730 740 750 760 770 780 790 800 810 820 830 840 850
200
250
300
350
400
450
500
550
600
650
VHavg (mV)
Crossing Point (mV)
550 mV
250 mV
250 + 0.5 (VHavg - 700)
550 + 0.5 (VHavg - 700)
Table 20. PECI DC Electrical Limits
Symbol Definition and Conditions Min Max Units Notes
1
V
in
Input Voltage Range -0.15 V
TT
V
V
hysteresis
Hysteresis 0.1 * V
TT
—V
2
V
n
Negative-edge threshold voltage 0.275 * V
TT
0.500 * V
TT
V
V
p
Positive-edge threshold voltage 0.550 * V
TT
0.725 * V
TT
V
I
source
High level output source
(V
OH
= 0.75 * V
TT)
-6.0 N/A mA
I
sink
Low level output sink
(V
OL
= 0.25 * V
TT
)
0.5 1.0 mA
I
leak+
High impedance state leakage to V
TT
N/A 50 µA
3
