
M68HC11
REFERENCE MANUAL
INSTRUCTION SET DETAILS
MOTOROLA
A-91
STA
Store Accumulator
STA
Operation:
(M)
(ACCX)
Description:
Stores the contents of ACCX in memory. The contents of ACCX remains
the same.
Condition Codes and Boolean Formulae:
N X7
Set if MSB of result is set; cleared otherwise.
Z X7 X6 X5 X4 X3 X2 X1 X0
Set if result is $00; cleared otherwise.
V 0
Cleared
Source Forms:
STAA (opr); STAB (opr)
Addressing Modes, Machine Code, and Cycle-by-Cycle Execution:
S
—
X
—
H
—
I
N
Z
V
0
C
—
—
Cycle
STAA (DIR)
Addr
Data
OP
OP+1
00dd
STAA (EXT)
Addr
Data
OP
OP+1
OP+2
hhll
STAA (IND,X)
Addr
Data
OP
A7
OP+1
FFFF
X+ff
(A)
STAA (IND,Y)
Addr
Data
OP
OP+1
OP+2
FFFF
Y+ff
(A)
R/W
1
1
1
R/W
1
1
1
1
R/W
1
1
1
1
R/W
1
1
1
1
0
1
2
3
4
5
97
dd
(A)
B7
hh
ll
(A)
18
A7
ff
—
ff
—
Cycle
STAB (DIR)
Addr
Data
OP
OP+1
00dd
STAB (EXT)
Addr
Data
OP
OP+1
OP+2
hhll
STAB (IND,X)
Addr
Data
OP
E7
OP+1
FFFF
X+ff
(B)
STAB (IND,Y)
Addr
Data
OP
OP+1
OP+2
FFFF
Y+ff
(B)
R/W
1
1
1
R/W
1
1
1
1
R/W
1
1
1
1
R/W
1
1
1
1
0
1
2
3
4
5
D7
dd
(B)
F7
hh
ll
(B)
18
E7
ff
—
ff
—