dsp56000 Freescale Semiconductor, Inc, dsp56000 Datasheet - Page 288

• Manufacturer Part Number: dsp56000
• Description: 24-bit Digital Signal Processor Family Manual
• Manufacturer: Freescale Semiconductor, Inc

Operation:
Description: Take the absolute value of the destination operand D and store the result
in the destination accumulator.
Example:
Explanation of Example: Prior to execution, the 56-bit A accumulator contains the
value $FF:FFFFFF:FFFFF2. Since this is a negative number, the execution of the ABS
instruction takes the twos complement of that value and returns $00:000000:00000E.
Note:
ABS instruction will cause an overflow to occur since the result cannot be correctly ex-
pressed using the standard 56-bit, fixed-point, twos-complement data representation.
Data limiting does not occur (i.e., A is not set to the limiting value of
$7F:FFFFFF:FFFFFF).
Condition Codes
S — Computed according to the definition in A.5 CONDITION CODE COMPUTATION.
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 overflow has occurred in A or B result
Note:
Refer to Section A.5 for complete details.
A - 22
ABS
| D |
ABS
For the case in which the D operand equals $80:000000:000000 (-256.0), the
The definitions of the E and U bits vary according to the scaling mode being used.
A
15
LF
D (parallel move)
A1
:
:
DM
14
$FF:FFFFFF:FFFFF2
:
#$123456,X0
Before Execution
13
T
Freescale Semiconductor, Inc.
**
12
For More Information On This Product,
MR
INSTRUCTION DESCRIPTIONS
S1
11
INSTRUCTION SET DETAILS
S0
10
Go to: www.freescale.com
Absolute Value
A,Y0
I1
9
I0
8
S
7
;take abs. value, set up X0, save value
Assembler Syntax:
A
L
6
ABS D (parallel move)
E
5
$00:000000:00000E
After Execution
U
4
CCR
N
3
Z
2
V
1
C
0
MOTOROLA
ABS