Omron SYSMAC CVM1 Series Operation Manual page 278

Symbol Math Instructions
Precautions
Flags
Using Signed Binary Addition Instructions
260
DOUBLE SIGNED BINARY ADD WITHOUT CARRY
When the execution condition is OFF, +L(401) is not executed. When the execu-
tion condition is ON, +L(401) adds the 8-digit contents of Au+1 and Au and the
8-digit contents of Ad+1 and Ad, and places the result in R and R + 1. CY will be
set if the result is greater than FFFF FFFF.
SIGNED BINARY ADD WITH CARRY
When the execution condition is OFF, +C(402) is not executed. When the execu-
tion condition is ON, +C(402) adds the contents of Au, Ad, and CY and places
the result in R. CY will be set if the result is greater than FFFF.
DOUBLE SIGNED BINARY ADD WITH CARRY
When the execution condition is OFF, +CL(403) is not executed. When the
execution condition is ON, +CL(403) adds the 8-digit contents of Au+1, Au, the
8-digit contents of Ad+1 and Ad, and CY, and places the result in R and R + 1. CY
will be set if the result is greater than FFFF FFFF.
Refer to page 101 for general precautions on operand data areas.
Content of *DM word is not BCD when set for BCD.
ER (A50003):
CY (A50004): The result is greater than FFFF or FFFF FFFF.
EQ (A50006): The result is 0.
N (A50008): Shows the status of bit 15 of R or R+1.
OF (A50009) Au (Au +1) and Ad (Ad +1) are both positive numbers and
the result is negative.
UF (A50010) Au (Au +1) and Ad (Ad +1) are both negative numbers and
the result is positive.
The range for signed data is –32,768 to 32,767 in decimal (–2,147,483,648 to
2,147,483,647 for "double" instructions), and 8000 to FFFF and 0000 to 7FFF in
hexadecimal (8000 0000 to FFFF FFFF and 0000 0000 to 7FFF FFFF for
"double" instructions).
Negative numbers are expressed as 2's complements. If the result of the addi-
tion is within the range of 8000 to FFFF, it represents a signed negative number
and the Negative Flag (A50008) turns ON.
Au +1 Au
Ad + 1 Ad
+
CY R + 1 R
Au
Ad
CY
+
CY R
Au +1 Au
Ad + 1 Ad
CY
+
CY R + 1 R
Section 5-20