Table of Contents
Advertisement
SUBD
(A : B) – (M : M + 1) ⇒ A : B
Operation:
Subtracts the content of memory location M : M + 1 from the content of
Description:
double accumulator D and places the result in D. For subtraction instruc-
tions, the C status bit represents a borrow.
Condition Codes and Boolean Formulas:
S
–
N:
Z:
V:
C:
Addressing Modes, Machine Code, and Execution Times:
Source Form
SUBD # opr16i
SUBD opr8a
SUBD opr16a
SUBD oprx0_xysp
SUBD oprx9,xyssp
SUBD oprx16,xysp
SUBD [D ,xysp ]
SUBD [ oprx16,xysp ]
CPU12
REFERENCE MANUAL
Subtract 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 a two's complement overflow resulted from the operation;
cleared otherwise.
D15 • M15 + M15 • R15 + R15 • D15
Set if the value of the content of memory is larger than the value of
the accumulator; cleared otherwise.
Address Mode
IMM
DIR
EXT
IDX
IDX1
IDX2
[D,IDX]
[IDX2]
INSTRUCTION GLOSSARY
V
C
∆
∆
Object Code
83 jj kk
93 dd
B3 hh ll
A3 xb
A3 xb ff
A3 xb ee ff
A3 xb
A3 xb ee ff
SUBD
Cycles
Access Detail
2
OP
3
RfP
3
ROP
3
RfP
3
RPO
4
fRPP
6
fIfRfP
6
fIPRfP
MOTOROLA
6-195
Advertisement
Table of Contents
