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ASL
55
Operation:
C
Assembler Syntax:
Description: Arithmetically shift the destination operand D one bit to the left and store
the result in the destination accumulator. The MS bit of D prior to instruction execution is
shifted into the carry bit C and a zero is shifted into the LS bit of the destination accumu-
lator D. If a zero shift count is specified, the carry bit is cleared. The difference between
ASL and LSL is that ASL operates on the entire 56 bits of the accumulator and therefore
sets the V bit if the number overflowed.
Example:
:
ASL A
(R3)–
:
Before Execution
A
$A5:012345:012345
SR
Explanation of Example: Prior to execution, the 56-bit A accumulator contains the
value $A5:012345:012345. The execution of the ASL A instruction shifts the 56-bit value
in the A accumulator one bit to the left and stores the result back in the A accumulator.
Condition Codes:
15
14
13
LF
T
**
L — Set if limiting (parallel move) or overflow has occurred in result
E — Set if the signed integer portion of A or B result is in use
U — Set if A or B result is unnormalized
N — Set if bit 55 of A or B result is set
Z— Set if A or B result equals zero
V — Set if bit 55 of A or B result is changed due to left shift
C — Set if bit 55 of A or B was set prior to instruction execution
A - 28
Freescale Semiconductor, Inc.
Arithmetic Shift Accumulator Left
47
ASL D (parallel move)
;multiply A by 2, update R3
$0300
12
11
10
9
8
S1
S0
I1
I0
**
MR
DSP56000/DSP56001 USER'S MANUAL
For More Information On This Product,
Go to: www.freescale.com
23
0
0 (parallel move)
After Execution
A
$4A:02468A:02468A
SR
$0373
7
6
5
4
3
2
L
E
U
N
Z
**
CCR
ASL
1
0
V
C
MOTOROLA
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