ADDRESSING
4 - 10 ADDRESS GENERATION UNIT
MOTOROLA
modifying the contents of Rn without an associated data move.
4.4.1.4 Postincrement By Offset Nn
The address of the operand is in the address register, Rn (see Table 4-1 and Figure 4-7).
After the operand address is used, it is incremented by the contents of the Nn register and
stored in the same address register. The contents of the Nn register are unchanged. This
mode can be used for making XY: memory references and for modifying the contents of
X MEMORY
23 0
0123456789ABCD
15 0
15 0
15 0
EXAMPLE: MOVE A1,X: (R0)
BEFORE EXECUTION AFTER EXECUTION
A2 A1 A0
55 48 47 24 23 0
7 0 23 0 23 0
X MEMORY
23 0
XXXXXX
$1000 $1000
A2 A1 A0
0 123456789ABCD
55 48 47 24 23 0
7 0 23 0 23 0
$1000
XXXX
$FFFF
R0
N0
M0
15 0
15 0
15 0
$1000
XXXX
$FFFF
R0
N0
M0
Assembler Syntax: (Rn)
Memory Spaces: P:, X:, Y:, XY:, L:
Additional Instruction Execution Time (Clocks): 0
Additional Effective Address Words: 0
$2345 6 7
Figure 4-4 Address Register Indirect — No Update