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LDD
(M : M + 1) ⇒ A : B
Operation:
Description:
Loads the contents of memory locations M and M+1 into double accu-
mulator D. The condition codes are set according to the data. The infor-
mation from M is loaded into accumulator A, and the information from
M+1 is loaded into accumulator B.
Condition Codes and Boolean Formulas:
S
–
N:
Z:
V:
Addressing Modes, Machine Code, and Execution Times:
Source Form
LDD # opr16i
LDD opr8a
LDD opr16a
LDD oprx0_xysp
LDD oprx9,xysp
LDD oprx16,xysp
LDD [D ,xysp ]
LDD [ oprx16,xysp ]
MOTOROLA
6-124
Load Double Accumulator
X
H
I
N
Z
∆
∆
–
–
–
Set if MSB of result is set; cleared otherwise.
Set if result is $0000; cleared otherwise.
0; Cleared.
Address Mode
IMM
DIR
EXT
IDX
IDX1
IDX2
[D,IDX]
[IDX2]
INSTRUCTION GLOSSARY
V
C
0
–
Object Code
CC jj kk
DC dd
FC hh ll
EC xb
EC xb ff
EC xb ee ff
EC xb
EC xb ee ff
LDD
Cycles
Access Detail
2
OP
3
RfP
3
ROP
3
RfP
3
RPO
4
fRPP
6
fIfRfP
6
fIPRfP
CPU12
REFERENCE MANUAL
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