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EC000 Core Processor
4-4
MC68307 USER’S MANUAL
MOTOROLA
An instruction’s addressing mode can specify the value of an operand, a register containing
the operand, or how to derive the effective address of an operand in memory. Each address-
ing mode has an assembler syntax. Some instructions imply the addressing mode for an
operand. These instructions include the appropriate fields for operands that use only one
addressing mode.
Table 4-2 lists a summary of the effective addressing modes for the pro-
cessor. Refer to M68000PM/AD,
M68000 Family Programmer’s Reference Manual, for
details on instruction format and addressing modes.
4.3.3 Notation Conventions
Table 4-3 lists the notation conventions used in this manual unless otherwise specified.
Table 4-2. Effective Addressing Modes
Addressing Modes
Syntax
Register Direct Addressing
Data Register Direct
Address Register Direct
EA = Dn
EA = An
Absolute Data Addressing
Absolute Short
Absolute Long
EA = (Next Word)
EA = (Next Two Words)
Program Counter Relative Addressing
Relative with Offset
Relative with Index and Offset
EA = (PC)+d16
EA = (PC)+d8
Register Indirect Addressing
Register Indirect
Postincrement Register Indirect
Predecrement Register Indirect
Register Indirect with Offset
Indexed Register Indirect with Offset
EA = (An)
EA = (An), An ¨ An+N
An ¨ An–N, EA = (An)
EA = (An)+d
16
EA = (An)+(Xn)+d8
Immediate Data Addressing
Immediate
Quick Immediate
DATA = Next Word(s)
Inherent Data
Implied Addressing
Implied Register
EA = SR, USP, SSP, PC
Table 4-3. Notation Conventions
Single and Double Operand Operations
+
Arithmetic addition or postincrement indicator.
–
Arithmetic subtraction or predecrement indicator.
×
Arithmetic multiplication.
÷
Arithmetic division or conjunction symbol.
~
Invert; operand is logically complemented.
Λ
Logical AND
V
Logical OR
≈
Logical exclusive OR
Source operand is moved to destination operand.
Two operands are exchanged.
<op>
Any double-operand operation.
<operand>tested
Operand is compared to zero and the condition codes are set appropriately.
sign-extended
All bits of the upper portion are made equal to the high-order bit of the lower portion.
Other Operations
TRAP
Equivalent to Format
÷ Offset Word (SSP); SSP – 2 SSP; PC (SSP); SSP – 4 SSP;
SR
(SSP); SSP – 2 SSP; (Vector) PC
STOP
Enter the stopped state, waiting for interrupts.
<operand>10
The operand is BCD; operations are performed in decimal.