Panasonic FP7 Series Command Reference Manual page 194

3.27 LOOP, LBL (LOOP, Label)
X100
1) TM instruction: Multiple timings occur during a single scan, therefore the time cannot be
guaranteed.
2) CT instruction: If the state of the count input does not change during the scan, it will
operate in the usual way.
3) SR instruction: If the state of the shift input does not change during the scan, it will operate
in the usual way.
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Precautions for programming
● When writing a label to an address before the LOOP instruction, pay attention to the
following:
(1) Be sure to write the instruction for setting the loop count before LBL - LOOP instructions.
(2) Be sure to write the instructions repeated between the LBL and LOOP instructions so that
they are executed with the same execution condition as the LOOP instruction.
(3) While repeating the program code, a single scan may exceed the WDT monitor time limit
and a WDT error may occur.
● The LOOP and LBL instructions cannot be used in the step ladder area (within the range
from the SSTP to STPE instructions).
● It is not possible to jump from the main program to a subprogram (subroutine or interruption
program after the ED instruction), from a subprogram to the main program, or between
subprograms.
● Be careful when using an instruction which detects the leading edge of the execution
condition and runs (1 - 6 below), including a differential instruction.
1) DF (leading edge differential) instruction
2) Count input for CT (counter) instruction
3) Count input for UDC (up-down counter) instruction
4) Shift input for SR (shift register) instruction
5) Shift input for LRSR (left and right shift register) instruction
6) Differential execution type high-level instruction (instruction specified by p and instruction
name)
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Flag operations
Name
SR7
SR8
(ER)
3-90
Description
Turns ON when the content of [S] is a negative value (the most significant bit is 1)
LBL 1
LOOP 1 DT 0
Executes repeatedly
when the execution
condition is on.
WUME-FP7CPUPGR-12