AMD-K6 datasheet(39/346 Pages) AMD

39 / 346 page

Chapter 3

Software Environment

20695H/0—March 1998

AMD-K6® Processor Data Sheet

Preliminary Information

Software Environment

This chapter provides a general overview of the AMD-K6

processor’s x86 software environment and briefly describes the

data types, registers, operating modes, interrupts, and

instructions supported by the AMD-K6 architecture and design

implementation.

3.1

Registers

The AMD-K6 processor contains all the registers defined by the

x86 architecture, including ge ne ral-purpose , segm ent,

floating-point, MMX, EFLAGS, control, task, debug, test, and

descriptor/memory-management registers. In addition, this

chapter provides information on the AMD-K6 Model-Specific

Registers (MSRs).

Note: Areas of the register designated as Reserved should not be

modified by software.

General-Purpose

Registers

The eight 32-bit x86 general-purpose registers are used to hold

integer data or memory pointers used by instructions. Table 2

contains a list of the general-purpose registers and the

functions for which they are used.

In order to support byte and word operations, EAX, EBX, ECX,

and EDX can also be used as 8-bit and 16-bit registers. The

shorter registers are overlaid on the longer ones. For example,

the name of the 16-bit version of EAX is AX (low 16 bits of

EAX) and the 8-bit names for AX are AH (high order bits) and

Table 2.

General-Purpose Registers

Function

EAX

Commonly used as an accumulator

EBX

Commonly used as a pointer

ECX

Commonly used for counting in loop operations

EDX

Commonly used to hold I/O information and to pass parameters

EDI

Commonly used as a destination pointer by the ES segment

ESI

Commonly used as a source pointer by the DS segment

ESP

Used to point to the stack segment

EBP

Used to point to data within the stack segment

AMD-K6 Datasheet(PDF) 39 Page - Advanced Micro Devices

AMD-K6 Datasheet(HTML) 39 Page - Advanced Micro Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL