Delta DVP-20PM

5 Applied Instructions and Basic Usage
DVP-20PM Application Manual
5-38
API
Applicable model
20PM
21
D
D
SUB
P
P
Binary subtraction

Bit device Word device
X Y M S K H KnX KnY KnM KnS T C D V Z
S
1
＊ ＊
＊ ＊ ＊ ＊ ＊ ＊ ＊ ＊ ＊
S
2
＊ ＊
＊ ＊ ＊ ＊ ＊ ＊ ＊ ＊ ＊
D
＊ ＊ ＊ ＊ ＊ ＊ ＊ ＊
 Note: The instruction supports V devices and Z devices. (If the 16-bit
instruction is used, Z devices can not be used. If the 32-bit
instruction is used, V devices can not be used.)
Please refer to specifications for more information about device
ranges.
16-bit instruction (7 steps)
SUB
Continuity
instruction
SUBP
Pulse
instruction
32-bit instruction (9 steps)
DSUB
Continuity
instruction
DSUBP
Pulse
instruction
 Flags
Ox O100
M1808 M1968 Zero flag
M1809 M1969 Borrow flag
M1810 M1970 Carry flag
 Please refer to the additional remark below.
Explanation
 The binary value in S
2
is subtracted from the binary value in S
1
, and the
difference is stored in D.
 S
1
: Minuend; S
2
: Subtrahend; D: Difference
 The highest bit in S
1
and the highest bit in S
2
are sign bits. If the sign bit in a
register is 0, the value in the register is a positive value. If the sign bit in a
register is 1, the value in the register is a negative value.
 The flags related to 16-bit binary subtraction and 32-bit binary subtraction are
listed below.
16-bit binary subtraction:
1. If the operation result gotten is 0, a zero flag will be ON.
2. If the operation result gotten is less than – 32,768, a borrow flag will be
ON.
3. If the operation result gotten is greater than 32,767, a carry flag will be ON.
32-bit binary subtraction:
1. If the operation result gotten is 0, a zero flag will be ON.
2. If the operation result gotten is less than – 2,147,483,648, a borrow flag will
be ON.
3. If the operation result gotten is greater than 2,147,483,647, a carry flag will
be ON.

Please refer to the additional remark on the instruction ADD for more
information about the relations between flags and values.
Example 1

16-bit binary subtraction: When X0 is ON, the subtrahend in D10 is subtracted
from the minuend in D0, and the difference is stored in D20.
X0
SUB D0 D10 D20
Example 2

When X1 is ON, the subtrahend in (D41, D40) is subtracted from the minuend
in (D31, D30), and the difference is stored in (D51, D50).
X
1
DSUB D30 D40 D50