Motorola Espresso Maker MC68340 ユーザーズマニュアル

MOTOROLA

MC68340 USER’S MANUAL

5- 13

Besides the operation code, which specifies the function to be performed, an instruction
defines the location of every operand for the function. Instructions specify an operand
location in one of three ways:

• Register Specification

A register field of the instruction contains the number of

the register.

• Effective Address

An effective address field of the instruction contains
address mode information.

• Implicit Reference

The definition of an instruction implies the use of
specific registers.

The register field within an instruction specifies the register to be used. Other fields within
the instruction specify whether the register is an address or data register and how it is to
be used. The M68000PM/AD,

M68000 Family Programmer’s Reference Manual, contains

detailed register information.

Except where noted, the following notation is used in this section:

Data

Immediate data from an instruction

Destination

Destination contents

Source

Source contents

Vector

Location of exception vector

Any address register (A7–A0)

Ax, Ay

Address registers used in computation

Any data register (D7–D0)

Control register (VBR, SFC, DFC)

Any address or data register

Dh, Dl

Data registers, high- and low-order 32 bits of product

Dr, Dq

Data registers, division remainder, division quotient

Dx, Dy

Data registers, used in computation

Dym, Dyn

Data registers, table interpolation values

Index register

[An]

Address extension

Condition code

Displacement

Example: d16 is a 16-bit displacement

〈

〉

Effective address

〈

data

〉

Immediate data; a literal integer

label

Assembly program label

list

List of registers

Example: D3–D0

[...]

Bits of an operand

Examples: [7] is bit 7; [31:24] are bits 31–24

Freescale Semiconductor, Inc.

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