Datasheet

Interfaces
28 Intel® Xeon® Processor 3400 Series Datasheet, Volume 1
2.4 Platform Environment Control Interface (PECI)
The PECI is a one-wire interface that provides a communication channel between
processor and a PECI master, usually the PCH. The processor implements a PECI
interface to:
• Allow communication of processor thermal and other information to the PECI
master.
• Read averaged Digital Thermal Sensor (DTS) values for fan speed control.
2.5 Interface Clocking
2.5.1 Internal Clocking Requirements
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Table 2-4. Processor Reference Clock Requirements
Reference Input Clocks Input Frequency Associated PLL
BCLK[0]/BCLK#[0] 133 MHz Processor/Memory
PEG_CLK/PEG_CLK# 100 MHz PCI Express/DMI