Delta VP3000 Series - Page 327

Chapter 7 Second Development Platform VP3000
318
API
Instruction
code
Operand Function
29 D NEG P D 2’s complement (negative)
Type
Operand
Bit devices Word devices
16-bit instruction (3 steps)
NEG
Continuous
execution
type
NEGP
Pulse
execution
type
32-bit instruction (5 steps)
DNEG
Continuous
execution
type
DNEGP
Pulse
execution
type
Associated flag: none
X Y M K H KnX KnY KnM T C D
D
    
Caution for using operand: none
Description
 Device to store 2’s complement
 Each bit in D is reverse (0  1, 1  0) at first, and then the least significant bit plus 1 and is
stored in the original register. This instruction can be used for converting a negative BIN value
into an absolute value.
 This instruction adopts pulse execution instructions (NEGP, DNEGP).
 Operand D uses device F, and they can only use 16-bit instructions.
Example
 Example 1
When X0 goes from OFF  ON, each bit in D10 is reverse (0  1, 1  0) at first, and then the
least significant bit plus 1 and is stored in D10.
X0
NEGP
D10
 Example 2
To obtain the absolute value of a negative value:
1. When the 15
th
bit of D0 is “1”, M0 = ON. (D0 is a negative value).
2. When M0 = ON, the absolute value of D0 can be obtained by NEG instruction.
M1000
BON D0 K15M0
M0
NEGP D0
 Example 3
Obtain the absolute value of the difference of the subtraction. When X0 = ON:
1. If D0 > D2, M0 = ON.
2. If D0 = D2, M1 = ON.
3. If D0 < D2, M2 = ON.
4. D4 is then able to remain positive.
X
0
CMP D0 D2 M0
M0
SUB D0 D2 D4
M2
SUB D2 D0 D4
M1