Statement List (STL) - DCE FEL ČVUT v Praze

Floating-Point Math Instructions
8.3.2 -R Subtract ACCU 1 from ACCU 2 as a Floating-Point Number
(32-Bit IEEE-FP)
Format
Description
Result
-R
Status word
-R (subtract 32-bit IEEE floating-point numbers) subtracts the contents of
accumulator 1 from the contents of accumulator 2 and stores the result in
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. 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 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.
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 - - - -
Statement List (STL) for S7-300 and S7-400 Programming
A5E00706960-01 8-5