Statement List (STL) - DCE FEL ČVUT v Praze

Accumulator Instructions
14.2 TAK Toggle ACCU 1 with ACCU 2
Format
Description
Status word
TAK
TAK (toggle ACCU 1 with ACCU 2) exchanges the contents of ACCU 1 with the
contents of ACCU 2. The instruction is executed without regard to, and without
affecting, the status bits. The contents of ACCU 3 and ACCU 4 remain unchanged
for CPUs with four ACCU s.
BR CC 1 CC 0 OV OS OR STA RLO /FC
writes: - - - - - - - - -
Example: Subtract smaller value from greater value
STL Explanation
L MW10 //Load contents of MW10 into ACCU 1-L.
L MW12 //Load contents of ACCU 1-L into ACCU 2-L. Load contents of MW12 into
ACCU 1-L.
>I //Check if ACCU 2-L (MW10) greater than ACCU 1-L (MW12).
SPB NEXT //Jump to NEXT jump label if ACCU 2 (MW10) is greater than ACCU 1 (MW12).
TAK //Swap contents ACCU 1 and ACCU 2
NEXT: -I //Subtract contents of ACCU 2-L from contents of ACCU 1-L.
T MW14 //Transfer result (= greater value minus smaller value) to MW14.
Contents ACCU 1 ACCU 2
before executing TAK instruction
after executing TAK instruction
Statement List (STL) for S7-300 and S7-400 Programming
14-2 A5E00706960-01