MC68030 Datasheet, PDF (54/602 Pages) Motorola, Inc – ENHANCED 32-BIT MICROPROCESSOR

Data Organization and Addressing Capabilities
2.4.11 Program Counter Indirect with Displacement Mode
In this mode, the operand is in memory. The address of the operand is the sum of the
address in the PC and the sign-extended 16-bit displacement integer in the extension word.
The value in the PC is the address of the extension word. The reference is a program space
reference and is only allowed for reads (refer to 4.2 Address Space Types).
GENERATION:
ASSEMBLER SYNTAX:
MODE:
REGISTER:
PROGRAM COUNTER:
EA = (PC) + d16
d16 ,PC)
111
010
31
0
ADDRESS OF EXTENSION WORD
31
15
0
DISPLACEMENT:
SIGN EXTENDED
INTEGER
+
MEMORY ADDRESS:
NUMBER OF EXTENSION WORDS: 1
31
0
OPERAND
2.4.12 Program Counter Indirect with Index (8-Bit Displacement) Mode
This mode is similar to the address register indirect with index (8-bit displacement) mode
described in 2.4.7 Address Register Indirect with Index (8-Bit Displacement) Mode, but
the PC is used as the base register. The operand is in memory. The address of the operand
is the sum of the address in the PC, the sign-extended displacement integer in the lower
eight bits of the extension word, and the sized, scaled, and sign-extended index operand.
The value in the PC is the address of the extension word. This reference is a program space
reference and is only allowed for reads. The user must include the displacement, the PC,
and the index register when specifying this addressing mode.
GENERATION:
ASSEMBLER SYNTAX:
MODE:
REGISTER:
PROGRAM COUNTER:
EA = (PC) + (Xn) + d8
(d ₈ , PC,Xn. SIZE*SCALE)
111
011
31
0
ADDRESS OF EXTENSION WORD
31
7
0
DISPLACEMENT:
SIGN EXTENDED
INTEGER
+
31
0
INDEX REGISTER
SIGN-EXTENDED VALUE
SCALE:
7
0
SCALE VALUE
X
+
31
0
MEMORY ADDRESS:
NUMBER OF EXTENSION WORDS: ¹
OPERAND
2-16
MC68030 USER’S MANUAL
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