Automationdirect.com DirectLOGIC DL205 Series User Manual page 313

Chapter 5: Standard RLL Instructions - Math
Multiply Real (MULR)
1
The Multiply Real instruction multiplies a real number in
230
the accumulator with either a real constant or a real number
240
occupying two consecutive V-memory locations. The result
2
250-1
resides in the accumulator. Both numbers must be Real
260 data type (IEEE floating point format).
3
DS Used
HPP N/A
4
5
Discrete Bit Flags
6
SP63
SP70
7
SP71
SP72
8
SP73
SP74
SP75
9
NOTE: Status flags are valid only until another instruction uses the same flag.
10
DirectSOFT
11
X1
12
13
14
A
Copy the result in the accumulator
to V1400 and V1401.
B
C
NOTE: The current HPP does not support real number entry with automatic conversion to the 32-bit IEEE
format. You must use DirectSOFT for this feature.
D
5–96
DL205 User Manual, 4th Edition, Rev. B
Operand Data Type
V-memory
Pointer
Constant
On when the result of the instruction causes the value in the accumulator to be zero.
On anytime the value in the accumulator is negative.
On anytime the V-memory specified by a pointer (P) is not valid.
On anytime the value in the accumulator is an invalid floating point number.
On when a signed addition or subtraction results in an incorrect sign bit.
On anytime a floating point math operation results in an underflow error.
On when a real number instruction is executed and a non-real number was encountered.
LDR
R 7.0
Load the real number 7.0
into the accumulator.
MULR
R 15.0
Multiply the accumulator
contents by the real number
15.0
8 4
OUTD
Acc. 0 1
V1400
Sign Bit
DL250-1 Range
A aaa
V All. (See page 3-55)
P All V-memory (See page 3-55) All V-memory (See page 3-56)
-3.402823E+038 to
R
+ 3.402823E+038
Description
4 0 E 0
7 4 0 E 0
(decimal)
x 1 5 X 4 1 7 0
1 0 5
Acc.
4 2 D 2
V1401
4 2 D 2
Real Value
2 1 8 4 2 1 8 4 2 1 8 4 2 1
0 0 0 0 1 0 1 1 0 1 0 0 1 0
Exponent (8 bits)
128 + 4 + 1 = 133 1.101001 x 2 (exp 6) = 1101001. binary= 105 decimal
133 - - 127 = 6
Implies 2 (exp 6)
MULR
A aaa
DL260 Range
aaa
All. (See page 3-56)
-3.402823E+038 to
+ 3.402823E+038
0 0 0 0
0 0 0 0 (Accumulator)
0 0 0 0 (MULR)
0 0 0 0
V1400
0 0 0 0 (Hex number)
8 4 2 1 8 4 2 1 8 4 2 1 8 4
0 0 0 0 0 0 0 0 0 0 0 0 0 0
Mantissa (23 bits)
2 1
0 0