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ASL
Operation:
Description:
Shifts all bits of memory location M one bit position to the left. Bit 0 is
loaded with a zero. The C status bit is loaded from the most significant
bit of M.
Condition Codes and Boolean Formulas:
S
–
N:
Z:
V:
C:
Addressing Modes, Machine Code, and Execution Times:
Source Form
ASL opr16a
ASL oprx0_xysp
ASL oprx9,xysp
ASL oprx16,xysp
ASL [D ,xysp ]
ASL [ oprx16,xysp ]
CPU12
REFERENCE MANUAL
Arithmetic Shift Left Memory
(same as LSL)
C
b7
X
H
I
N
Z
∆
∆
–
–
–
Set if MSB of result is set; cleared otherwise.
Set if result is $00; cleared otherwise.
N ⊕ C = [N • C] + [N • C] (for N and C after the shift)
Set if (N is set and C is cleared) or (N is cleared and C is set); cleared oth-
erwise (for values of N and C after the shift).
M7
Set if the MSB of M was set before the shift; cleared otherwise.
Address Mode
EXT
IDX
IDX1
IDX2
[D,IDX]
[IDX2]
INSTRUCTION GLOSSARY
b0
– – – – – –
V
C
∆
∆
Object Code
78 hh ll
68 xb
68 xb ff
68 xb ee ff
68 xb
68 xb ee ff
ASL
0
Cycles
Access Detail
4
rOPw
3
rPw
4
rPOw
5
frPPw
6
fIfrPw
6
fIPrPw
MOTOROLA
6-19
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