!
!
31
word that is non-existent.
When the ER Flag is ON, the current instruction
will not be executed.
3-4-13
Arithmetic Flags
The following flags are used in data shifting, arithmetic calculation, and com-
parison instructions. They are generally referred to only by their two-letter
abbreviations.
Caution
These flags are all reset when the END instruction is executed, and therefore
cannot be monitored from a programming device.
Refer to
5-12 Data Shifting
,
5-14 Data Comparison
,
5-16 BCD Calculations
,
and
5-17 Binary Calculations
for details.
SR bit 25504 turns ON when there is a carry in the result of an arithmetic op-
eration or when a rotate or shift instruction moves a “1” into CY. The content
of CY is also used in some arithmetic operations, e.g., it is added or sub-
tracted along with other operands. This flag can be set and cleared from the
program using the SET CARRY and CLEAR CARRY instructions.
SR bit 25505 turns ON when the result of a comparison shows the second of
two operands to be greater than the first.
SR bit 25506 turns ON when the result of a comparison shows two operands
to be equal or when the result of an arithmetic operation is zero.
SR bit 25507 turns ON when the result of a comparison shows the second of
two operands to be less than the first.
Caution
The previous four flags are cleared when END(01) is is executed.
3-5
AR (Auxiliary Relay) Area
The AR area consists of two parts. The first part, words AR 00 through AR 06
(bits AR 0000 through AR 0615), may be used by the user as work words or
work bits. The rest of the AR area, words AR 07 through AR 27 (bits AR 0700
through AR 2715), is dedicated for various flags, control bits, and operating
parameters.
AR 07 through AR 15 are used for the SYSMAC LINK System; AR 16 and
AR 17 are used for both the SYSMAC LINK System and the SYSMAC NET
Link System; and AR 19 through AR 21 are used with the File Memory Unit.
When not used for their prescribed purposes, these words may be used as
work bits.
The AR area retains status during power interruptions, when switching from
MONITOR or RUN mode to PROGRAM mode, or when PC operation is
stopped. Bit allocations are shown in the following table and described in the
following pages in order of bit number.
Carry Flag, CY
Greater Than Flag, GR
Equal Flag, EQ
Less Than Flag, LE
AR Area
Section 3-5
