Statement List (STL) - DCE FEL ČVUT v Praze

Integer Math Instructions
7.10 *D Multiply ACCU 1 and ACCU 2 as Double Integer
(32-Bit)
Format
Description
*D
Status word
Example
*D (multiply 32-bit integer numbers) multiplies the contents of ACCU 2 by the
contents of ACCU 1. The contents of ACCU 1 and ACCU 2 are interpreted as 32-bit
integer numbers. The result is stored in accumulator 1 as a 32-bit integer number. If
the status word bits are OV1 = 1 and OS = 1, the result is outside the range of a
32-bit integer number.
The instruction is executed without regard to, and without affecting, the RLO. The
status word bits CC 1, CC 0, OS, and OV are set as a function of the 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.
See also Evaluating the Bits of the Status Word with Integer Math Instructions.
BR CC 1 CC 0 OV OS OR STA RLO /FC
writes: - x x x x - - - -
Status bit generation CC 1 CC 0 OV OS
Product = 0 0 0 0 -
-2147483648 = Product > 0 1 0 0 -
Product > 2147483647 1 0 1 1
Product < -2147483648 0 1 1 1
STL Explanation
L ID10 //Load the value of ID10 into ACCU 1.
L MD14 //Load contents of ACCU 1 into ACCU 2. Load contents of MD14 into ACCU
1.
*D //Multiply ACCU 2 and ACCU 1; store the result in ACCU 1.
T DB1.DBD25 //The contents of ACCU 1 (result) are transferred to DBD25 in DB1.
Statement List (STL) for S7-300 and S7-400 Programming
7-12 A5E00706960-01