Table of Contents
Advertisement
CPD
(A : B) – (M : M + 1)
Operation:
Description:
Compares the content of double accumulator D with a 16-bit value at the
address specified, and sets the condition codes accordingly. The com-
pare is accomplished internally by a 16-bit subtract of (M : M + 1) from D
without modifying either D or (M : M + 1).
Condition Codes and Boolean Formulas:
S
–
N:
Z:
V:
C:
Addressing Modes, Machine Code, and Execution Times:
Source Form
CPD # opr16i
CPD opr8a
CPD opr16a
CPD oprx0_xysp
CPD oprx9,xysp
CPD oprx16,xysp
CPD [D ,xysp ]
CPD [ oprx16,xysp ]
CPU12
REFERENCE MANUAL
Compare Double Accumulator
X
H
I
N
Z
∆
∆
–
–
–
Set if MSB of result is set; cleared otherwise.
Set if result is $0000; cleared otherwise.
D15 • M15 • R15 + D15 • M15 • R15
Set if two's complement overflow resulted from the operation; cleared
otherwise.
D15 • M15 + M15 • R15 + R15 + D15
Set if the absolute value of the content of memory is larger than the
absolute value of the accumulator; cleared otherwise.
Address Mode
IMM
DIR
EXT
IDX
IDX1
IDX2
[D,IDX]
[IDX2]
INSTRUCTION GLOSSARY
V
C
∆
∆
Object Code
8C jj kk
9C dd
BC hh ll
AC xb
AC xb ff
AC xb ee ff
AC xb
AC xb ee ff
CPD
Cycles
Access Detail
2
OP
3
RfP
3
ROP
3
RfP
3
RPO
4
fRPP
6
fIfRfP
6
fIPRfP
MOTOROLA
6-65
Advertisement
Table of Contents
