Statement List (STL) - DCE FEL ČVUT v Praze

Floating-Point Math Instructions
8.3.3 *R Multiply ACCU 1 and ACCU 2 as Floating-Point Numbers
(32-Bit IEEE-FP)
Format
*R
Description of instruction
Result
Status word
Example
*R (multiply 32-bit IEEE floating-point numbers) multiplies the contents of
accumulator 2 by the contents of accumulator 1. The contents of accumulator 1 and
accumulator 2 are interpreted as 32-bit IEEE floating-point numbers. The result is
stored in accumulator 1 as a 32-bit IEEE floating-point number. The instruction is
executed without regard to, and without affecting, the RLO. The status bits CC 1, CC
0, OS, and OV are set as a result of the instruction.
The contents of accumulator 2 remain unchanged for CPUs with two ACCUs.
The contents of accumulator 3 are copied into accumulator 2, and the contents of
accumulator 4 are copied into accumulator 3 for CPUs with four ACCUs. The
contents of accumulator 4 remain unchanged.
The result in ACCU 1 is CC 1 CC 0 OV OS Note
+qNaN 1 1 1 1
+infinite 1 0 1 1 Overflow
+normalized 1 0 0 -
+denormalized 0 0 1 1 Underflow
+zero 0 0 0 -
-zero 0 0 0 -
-denormalized 0 0 1 1 Underflow
-normalized 0 1 0 -
-infinite 0 1 1 1 Overflow
-qNaN 1 1 1 1
BR CC 1 CC 0 OV OS OR STA RLO /FC
writes: - x x x x - - - -
STL Explanation
OPN DB10
L ID10 //Load the value of ID10 into ACCU 1.
L MD14 //Load the value of ACCU 1 into ACCU 2. Load the value of MD14 into ACCU 1.
*R //Multiply ACCU 2 and ACCU 1; store the result in ACCU 1.
T DBD25 //The content of ACCU 1 (result) is transferred to DBD25 in DB10.
Statement List (STL) for S7-300 and S7-400 Programming
A5E00706960-01 8-7