Table of Contents
Advertisement
II
CMPM
Operation:
Assembler
Syntax:
Attributes:
Compare Memory
CMPM
Destination - Source
=>
cc
CMPM (Ay)+, (Ax)+
Size
=
(Byte, Word, Long)
Description:
Subtracts the source operand from the destination operand and sets the condition
codes according to the results. The destination location is not changed. The operands are
always addressed with the postincrement addressing mode, using the address registers specified
by the instruction.
Condition Codes:
x
N
Z
v
c
X Not affected.
N Set if the result is negative. Cleared otherwise.
Z Set if the result is zero. Cleared otherwise.
V Set if an overflow is generated. Cleared otherwise.
C Set if a borrow is generated. Cleared otherwise.
Instruction Format:
15
14
13
12
11
10
9
8
7
6
o
REGISTER
Ax
SIZE
Instruction Fields:
5
4
3
2
0
o
I
0
I
REGISTERAy
Register Ax field -
(always the destination). Specifies an address register in the postincrement
addressing mode.
Size field - Specifies the size of the operation:
00 - Byte operation
01 - Word operation
10 -
Long operation
Register Ay field -
(always the source). Specifies an address register in the postincrement
addressing mode.
MOTOROLA
4-66
INSTRUCTION SET
CPU32 REFERENCE MANUAL
Advertisement
Table of Contents
