Intel architecture ia-32 User Manual
Vol. 3A 17-1
CHAPTER 17
IA-32 ARCHITECTURE COMPATIBILITY
All IA-32 processors are binary compatible. Compatibility means that, within certain limited
constraints, programs that execute on previous generations of IA-32 processors will produce
identical results when executed on later IA-32 processors. The compatibility constraints and any
implementation differences between the IA-32 processors are described in this chapter.
constraints, programs that execute on previous generations of IA-32 processors will produce
identical results when executed on later IA-32 processors. The compatibility constraints and any
implementation differences between the IA-32 processors are described in this chapter.
Each new IA-32 processor has enhanced the software visible architecture from that found in
earlier IA-32 processors. Those enhancements have been defined with consideration for
compatibility with previous and future processors. This chapter also summarizes the compati-
bility considerations for those extensions.
earlier IA-32 processors. Those enhancements have been defined with consideration for
compatibility with previous and future processors. This chapter also summarizes the compati-
bility considerations for those extensions.
17.1. IA-32 PROCESSOR FAMILIES AND CATEGORIES
IA-32 processors are referred to in several different ways in this chapter, depending on the type
of compatibility information being related, as described in the following:
of compatibility information being related, as described in the following:
•
IA-32 Processors — All the Intel processors based on the Intel IA-32 Architecture, which
include the 8086/88, Intel 286, Intel386, Intel486, Pentium, Pentium Pro, Pentium II,
Pentium III, Pentium 4, and Intel Xeon processors.
include the 8086/88, Intel 286, Intel386, Intel486, Pentium, Pentium Pro, Pentium II,
Pentium III, Pentium 4, and Intel Xeon processors.
•
32-bit Processors — All the IA-32 processors that use a 32-bit architecture, which include
the Intel386, Intel486, Pentium, Pentium Pro, Pentium II, Pentium III, Pentium 4, and Intel
Xeon processors.
the Intel386, Intel486, Pentium, Pentium Pro, Pentium II, Pentium III, Pentium 4, and Intel
Xeon processors.
•
16-bit Processors — All the IA-32 processors that use a 16-bit architecture, which include
the 8086/88 and Intel 286 processors.
the 8086/88 and Intel 286 processors.
•
P6 Family Processors — All the IA-32 processors that are based on the P6 microarchi-
tecture, which include the Pentium Pro, Pentium II, and Pentium III processors.
tecture, which include the Pentium Pro, Pentium II, and Pentium III processors.
•
Pentium 4 Family Processors — A family of IA-32 processors that is based on the Intel
NetBurst microarchitecture.
NetBurst microarchitecture.
•
Intel Xeon Family Processors — A family of IA-32 processors that is based on the Intel
NetBurst microarchitecture. This family includes the Intel Xeon processor and the Intel
Xeon processor MP.
NetBurst microarchitecture. This family includes the Intel Xeon processor and the Intel
Xeon processor MP.
•
Pentium D Processors — A family of dual-core IA-32 processors that provides two
processor cores in a physical package. Each core is based on the Intel NetBurst microar-
chitecture.
processor cores in a physical package. Each core is based on the Intel NetBurst microar-
chitecture.
•
Pentium Processor Extreme Editions — A family of dual-core IA-32 processors that
provides two processor cores in a physical package. Each core is based on the Intel
NetBurst microarchitecture and supports Hyper-Threading Technology.
provides two processor cores in a physical package. Each core is based on the Intel
NetBurst microarchitecture and supports Hyper-Threading Technology.