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MOVB
Operation:
(M
1
Description:
Moves the content of one memory location to another memory location.
The content of the source memory location is not changed.
Move instructions use separate addressing modes to access the source
and destination of a move. The following combinations of addressing
modes are supported: IMM–EXT, IMM–IDX, EXT–EXT, EXT–IDX, IDX–
EXT, and IDX–IDX. IDX operands allow indexed addressing mode spec-
ifications that fit in a single postbyte; including 5-bit constant, accumula-
tor offsets, and auto increment/decrement modes. Nine-bit and 16-bit
constant offsets would require additional extension bytes and are not al-
lowed. Indexed indirect modes (for example [D,r]) are also not allowed.
There are special considerations when using PC-relative addressing
with move instructions. These are discussed in
Multiple
Condition Codes and Boolean Formulas:
S
–
None affected.
Addressing Modes, Machine Code, and Execution Times:
1
Source Form
MOVB # opr8 , opr16a
MOVB # opr8i, oprx0_xysp
MOVB opr16a, opr16a
MOVB opr16a, oprx0_xysp
MOVB oprx0_xysp, opr16a
MOVB oprx0_xysp, oprx0_xysp
Notes:
1. The first operand in the source code statement specifies the source for the move.
MOTOROLA
6-144
Move a Byte of Data
from One Memory Location to Another
) ⇒ M
2
Modes.
X
H
I
N
Z
–
–
–
–
–
Address Mode
IMM–EXT
IMM–IDX
EXT–EXT
EXT–IDX
IDX–EXT
IDX–IDX
INSTRUCTION GLOSSARY
V
C
–
–
Object Code
18 0B ii hh ll
18 08 xb ii
18 0C hh ll hh ll
18 09 xb hh ll
18 0D xb hh ll
18 0A xb xb
MOVB
3.9 Instructions Using
Cycles
Access Detail
4
OPwP
4
OPwO
6
OrPwPO
5
OPrPw
5
OrPwP
5
OrPwO
CPU12
REFERENCE MANUAL
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