Vol. 1 3-3

BASIC EXECUTION ENVIRONMENT

Figure 3-1.  IA-32 Basic Execution Environment for Non-64-bit Modes

0

2^32 -1

Eight 32-bit

32-bits

32-bits

General-Purpose Registers

Segment Registers

EFLAGS Register

EIP (Instruction Pointer Register)

Address Space*

*The address space can be

Six 16-bit

Registers

Registers

Eight 80-bit

Registers

Floating-Point

Data Registers

Eight 64-bit

Registers

MMX Registers

flat or segmented. Using

XMM Registers

Eight 128-bit

Registers

16 bits

Control Register

16 bits

Status Register

48 bits

FPU Instruction Pointer Register

48 bits

FPU Data (Operand) Pointer Register

FPU Registers

MMX Registers

XMM Registers

32-bits

MXCSR Register

Opcode Register (11-bits)

Basic Program Execution Registers

16 bits

Tag Register

the physical address

extension mechanism, a

physical address space of

2^36 - 1 can be addressed.

YMM Registers

Eight 256-bit

Registers

YMM Registers

Four 128-bit Registers

Bounds Registers

BNDCFGU

BNDSTATUS