Program Counter Indirect With Displacement Mode; Mode - Motorola MC68030 User Manual

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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:
MOOE:
REGISTER:
PROGRAM COUNTER:
DISPLACEMENT:
MEMORY ADDRESS:
EA
=
(PC! + d16
(d16. PC )
111
010
·31 15
31
AODRESS OF EXTENSION WORD
r--------
r---------,
L __ S~N...:X~~~ _
INTEGER
I - - - - + (
31
OPERAND
NUMBER OF EXTENSION WORDS:
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 dis-
placement) 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.
2-16
GENERATION:
ASSEMBLER SYNTAX:
MODE:
REGISTER:
, PROGRAM COUNTER:
DISPLACEMENT:
INDEX REGISTER:
SCALE:
MEMORY ADDRESS:
31
EA = (PC) +
(Xn)
+
dS
(ds.PC.Xn,SIZE ·SCALE)
111
011
31
,------------
L _ _ _
"':I~ E~E~E~
_ _ _ _ ' - -_ _
...I
31
SIGN EXTENDED VALUE
SCALE VALUE
31
NUMBER OF EXTENSION WORDS:
MC68030 USER'S MANUAL
ADDRESS OF EXTENSION WORD
OPERAND
MOTOROLA