Intel Pentium D 940 HH80553PG0884M User Manual

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The Intel Pentium D processor 900 sequence supports Enhanced Intel

® 

SpeedStep

®

 

technology that allows trade-offs to be made between performance and power 

consumptions. This may lower average power consumption (in conjunction with OS 

support).

The Pentium D processors 960, 950, 940, 930, and 920, and the Pentium processor 

Extreme Edition 955, 965 support Intel

®

 Virtualization Technology. Intel Virtualization 

Technology provides silicon-based functionality that works together with compatible 

Virtual Machine Monitor (VMM) software to improve upon software-only solutions. 

Because this virtualization hardware provides a new architecture upon which the 

operating system can run directly, it removes the need for binary translation. Thus, it 

helps eliminate associated performance overhead and vastly simplifies the design of 

the VMM, in turn allowing VMMs to be written to common standards and to be more 

robust. See the Intel

Architecture for more details.

The processor includes an address bus powerdown capability which removes power 

from the address and data signals when the FSB is not in use. This feature is always 

enabled on the processor.

A ‘#’ symbol after a signal name refers to an active low signal, indicating a signal is in 

the active state when driven to a low level. For example, when RESET# is low, a reset 

has been requested. Conversely, when NMI is high, a nonmaskable interrupt has 

occurred. In the case of signals where the name does not imply an active state but 

describes part of a binary sequence (such as address or data), the ‘#’ symbol implies 

that the signal is inverted. For example, D[3:0] = ‘HLHL’ refers to a hex ‘A’, and 

D[3:0]# = ‘LHLH’ also refers to a hex ‘A’ (H= High logic level, L= Low logic level).

Front Side Bus” refers to the interface between the processor and system core logic 

(a.k.a. the chipset components). The FSB is a multiprocessing interface to processors, 

memory, and I/O.

Commonly used terms are explained here for clarification:

• Intel

the 775-land LGA package — Processor in the FC-LGA6 package with two 2 MB 

L2 caches

1

.

• Intel

land LGA package — Processor in the FC-LGA6 package with two 2 MB L2 

• Processor — For this document, the term processor is the generic term for the 

Intel Pentium D processor 900 sequence and Intel Pentium processor Extreme 

Edition 955, 965.

• Keep-out zone — The area on or near the processor that system design can not 

use. 

• Intel

 945G/945GZ/945P/945PL Express chipsets — Chipset that supports 

DDR2 memory technology for the processor.

• Intel

 955X Express chipset — Chipset that supports DDR2 memory technology 

for the processor.

1. Total accessible size of L2 caches may vary by one cache line pair (128 bytes), depending on 

usage and operating environment.