Peci Interface; Platform Environment Control Interface (Peci); Wrpkgconfig(); Rdiamsr() - Intel BX80619I73820 Design Manual

PECI Interface

7
PECI Interface
7.1

Platform Environment Control Interface (PECI)

The Platform Environment Control Interface (PECI) uses a single wire for self-clocking
and data transfer. The bus requires no additional control lines. The physical layer is a
self-clocked one-wire bus that begins each bit with a driven, rising edge from an idle
level near zero volts. The duration of the signal driven high depends on whether the bit
value is a logic '0' or logic '1'. PECI also includes variable data transfer rate established
with every message. In this way, it is highly flexible even though underlying logic is
simple.
The interface design was optimized for interfacing to Intel processor and chipset
components in both single processor and multiple processor environments. The single
wire interface provides low board routing overhead for the multiple load connections in
the congested routing area near the processor and chipset components. Bus speed,
error checking, and low protocol overhead provides adequate link bandwidth and
reliability to transfer critical device operating conditions and configuration information.
The PECI bus offers:
• A wide speed range from 2 Kbps to 2 Mbps
• CRC check byte used to efficiently and atomically confirm accurate data delivery
• Synchronization at the beginning of every message minimizes device timing
accuracy requirements
Generic PECI specification details are out of the scope of this document. What follows is
a processor-specific PECI client definition, and is largely an addendum to the PECI
Network Layer and Design Recommendations sections for the PECI specification.
Note: The PECI commands described in this document apply primarily to the Intel
3960X, i7-3970X processor Extreme Edition, Intel
®
Intel Core™ i7-3820 processor. The these processors utilizes the capabilities
described in this document to indicate support for four memory channels. Refer to
Table 7-1
3970X processor Extreme Edition, Intel
i7-3820 processor.
Table 7-1.

Summary of Processor-specific PECI Commands

Command
GetTemp()
RdPkgConfig()

WrPkgConfig()

RdIAMSR()

WrIAMSR()
RdPCIConfig()
WrPCIConfig()
RdPCIConfigLocal()
WrPCIConfigLocal()
Thermal/Mechanical Specifications and Design Guide
for the list of PECI commands supported by the Intel
®
Intel Core™ i7-3960X, i7-3970X Processor
Extreme Edition, Intel
Processor, and Intel
Ping()
GetDIB()
®
Core™ i7-3930K processor, and
®
Core™ i7-3930K processor, and Intel
Supported on
®
Core™ i7-3930K
®
Core™ i7-3820
Processor
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
No
Yes
Yes
®
Core™ i7-
®
Core™ i7-3960X, i7-
®
Core™
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