376 datasheet(12/95 Pages) INTEL

12 / 95 page

376 EMBEDDED PROCESSOR

Table 23 Segment Register Selection Rules

Type of

Implied (Default)

Segment Override

Memory Reference

Segment Use

Prefixes Possible

Code Fetch

None

Destination of PUSH PUSHF INT

None

CALL PUSHA Instructions

Source of POP POPA POPF IRET

None

RET Instructions

Destination of STOS

MOVS REP STOS

None

REP MOVS Instructions

(DI is Base Register)

Other Data References

with Effective Address

Using Base Register of

EAX

CS SS ES FS GS

EBX

CS SS ES FS GS

ECX

CS SS ES FS GS

EDX

CS SS ES FS GS

ESI

CS SS ES FS GS

EDI

CS SS ES FS GS

EBP

CS SS ES FS GS

ESP

CS SS ES FS GS

24 Addressing Modes

The 80376 provides a total of 8 addressing modes

for instructions to specify operands The addressing

modes are optimized to allow the efficient execution

of high level languages such as C and FORTRAN

and they cover the vast majority of data references

needed by high-level languages

Two of the addressing modes provide for instruc-

tions that operate on register or immediate oper-

ands

The operand is located in

one of the 8- 16- or 32-bit general registers

Immediate Operand Mode

The operand is includ-

ed in the instruction as part of the opcode

The remaining 6 modes provide a mechanism for

specifying the effective address of an operand The

linear address consists of two components the seg-

ment base address and an effective address The

effective address is calculated by summing any

combination of the following three address elements

(see Figure 23)

DISPLACEMENT

an 8- 16- or 32-bit immediate val-

ue following the instruction

BASE

The contents of any general purpose regis-

ter The base registers are generally used by compil-

ers to point to the start of the local variable area

Note that if the Address Length Prefix is used only

BX and BP can be used as a BASE register

INDEX

The contents of any general purpose regis-

ter except for ESP The index registers are used to

access the elements of an array or a string of char-

acters The index register’s value can be multiplied

by a scale factor either 1 2 4 or 8 The scaled index

is especially useful for accessing arrays or struc-

tures Note that if the Address Length Prefix is

used no Scaling is available and only the registers

SI and DI can be used to INDEX

376 Datasheet(PDF) 12 Page - Intel Corporation

376 Datasheet(HTML) 12 Page - Intel Corporation

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

Datasheet Download

Link URL