Statement List (STL) - DCE FEL ČVUT v Praze

Floating-Point Math Instructions
8.2 Evaluating the Bits of the Status Word with
Floating-Point Math Instructions
Description
The basic arithmetic types influence the following bits in the Status word: CC 1 and
CC 0, OV and OS.
The following tables show the signal state of the bits in the status word for the results
of instructions with floating-point numbers (32 bits):
Valid Area for a Result CC 1 CC 0 OV OS
+0, -0 (Null) 0 0 0 *
-3.402823E+38 < result < -1.175494E-38 (negative number) 0 1 0 *
+1.175494E-38 < result < 3.402824E+38 (positive number) 1 0 0 *
* The OS bit is not affected by the result of the instruction.
Invalid Area for a Result CC 1 CC 0 OV OS
Underflow
-1.175494E-38 < result < - 1.401298E-45 (negative number)
0 0 1 1
Underflow
+1.401298E-45 < result < +1.175494E-38 (positive number)
0 0 1 1
Overflow
Result < -3.402823E+38 (negative number)
0 1 1 1
Overflow
Result > 3.402823E+38 (positive number)
1 0 1 1
Not a valid floating-point number or illegal instruction
(input value outside the valid range)
1 1 1 1
Statement List (STL) for S7-300 and S7-400 Programming
8-2 A5E00706960-01