Texas Instruments TMS320C3x 사용자 설명서

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페이지 757
 Absolute Value of Floating Point
ABSF
13-41
  Assembly Language Instructions
Syntax
ABSF  
src, dst
Operation
|
src| 
 dst
Operands
src general addressing modes (G):
0 0
register (R
n, 0 
 
 7)
0 1
direct
1 0
indirect (disp = 0–255, IR0, IR1)
1 1
immediate
dst
register (R
n, 0 
  
 7)
Opcode
31
24 23
16
8 7
0
15
0 0 0 0 0
0
src
0
dst
G
0
0
Description
The absolute value of the 
src operand is loaded into the dst register. The src
and 
dst operands are assumed to be floating-point numbers.
An overflow occurs if 
src (man) = 80000000h and src (exp) = 7Fh. The result
is 
dst (man) = 7FFFFFFFh and dst (exp) = 7Fh.
Cycles
1
Status Bits
These condition flags are modified only if the destination register is R7– R0.
LUF
Unaffected
LV
1 if a floating-point overflow occurs; unchanged otherwise
UF
0
N
0
Z
1 if a 0 result is generated; 0 otherwise
V
1 if a floating-point overflow occurs; 0 otherwise
C
Unaffected
Mode Bit
OVM
Operation is not affected by OVM bit value.
Example
ABSF
R4,R7
Before Instruction
After Instruction
R4
5C 8000 F971
R4
5C 8000 F971
R7
7D 2511 00AE
R7
5C 7FFF 068F
LUF
0
LUF
0
LV
0
LV
0
UF
0
UF
0
N
0
N
0
Z
0
Z
0
V
0
V
0
C
0
C
0
5.48527255e+37
–9.90337307e+27
9.90337307e+27
–9.90337307e+27