INSTRUCTION DESCRIPTIONS
A - 172 INSTRUCTION SET DETAILS
MOTOROLA
Operation: Assembler Syntax:
( . . . . . ); ea
➞
Rn ( . . . . . ) ea
where ( . . . . . ) refers to any arithmetic or logical instruction which allows parallel moves.
Description:
Update the specified address register according to the specified effective
addressing mode. All update addressing modes may be used.
Example:
:
RND B (R3)+N3 ;round value in B into B1, R3+N3
➞
R3
:
Explanation of Example:
Prior to execution, the 16-bit address register R3 contains the
value $0007, and the 16-bit address offset register N3 contains the value $0004. The
execution of the parallel move portion of the instruction, (R3)+N3, updates the R3
address register according to the specified effective addressing mode by adding the
value in the R3 register to the value in the N3 register and storing the 16-bit result back in
the R3 address register.
Condition Codes:
The condition codes are not affected by this type of parallel move.
UAddress Register Update U
N3 N3
$0004 $0004
Before Execution After Execution
R3 R3
$0007 $000B
MR CCR
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
LF DM T ** S1 S0 I1 I0 S L E U N Z V C