Programmer (HHP) User guide

Chapter 10
Using Math Instructions
10–8
Use the MUL instruction to multiply one value (source A) by another
(source B) and place the result in the destination.
Source A and B can either be a word address or a constant, however both
sources cannot be a constant. The destination must be a word address.
If the result is larger than +32,767 or smaller than –32,767 (16-bits), the
32-bit result is placed in the math register.
Updates to Arithmetic Status Bits
With this Bit: The Controller:
S0/0 Carry (C) always resets.
S0/1 Overflow (V)
sets if overflow is detected at destination; otherwise resets.
On overflow, the minor error flag is also set. The value
–32,768 or 32,767 is placed in the destination. If S2/14
(math overflow selection bit) is set, then the unsigned,
truncated overflow remains in the destination.
S0/2 Zero (Z) sets if result is zero; otherwise resets.
S0/3 Sign (S) sets if result is negative; otherwise resets.
Entering the Instruction
You enter the instruction from within the program monitor functional area.
P
0 0 0 M U L S R C A
N 4 0
P
0 0 0 M U L S R C B
6 0
P
0 0 0 M U L D E S T
N 6 0
Changes to the Math Register
The math register contains the 32-bit signed integer result of the multiply
operation. This result is valid at overflow.
MUL
MULTIPLY
Source A N7:4
0
Source B 60
Dest N7:6
0
Execution Times (µ sec) when:
True False
57.96 6.78
Ladder representation:
Multipl
y (
M
U
L
)
2
L
8
FUN
ENT
To enter the function code, press: