Floating-Point Multiply: *F(456) - Omron SYSMAC CV Series Operation Manual

Floating-point Math Instructions

5-21-7 FLOATING-POINT MULTIPLY: *F(456)

Ladder Symbol
(456)
*F
Md
Variations
*F(456)
Description
Multiplier
0
Numeral
+R
–R
NaN
Precautions
Flags
UF (A50010): Absolute value of the result is less than the minimum value
that can be expressed for floating-point data.
Operand Data Areas
Md: First multiplicand word
Mr R
Mr: First multiplier word
R: First result word
When the execution condition OFF, *F(456) is not executed. When the execu-
tion condition is ON, *F(456) multiplies the 32-bit floating-point content of Md
and Md +1 by the 32-bit floating-point content of Mr and Mr +1 and places the
result in R and R+1.
Md+1
x
Mr+1
R+1
If the absolute value of the result is greater than the maximum value that can be
expressed for floating-point data, the Overflow Flag (A50009) will turn ON and
the result will be output as R.
If the absolute value of the result is less than the minimum value that can be ex-
pressed for floating-point data, the Underflow Flag (A50010) will turn ON and the
result will be output as 0.
The various combinations of multiplicand and multiplier data will produce the re-
sults shown in the following table.
0 Numeral
0 0
0
See note 1.
ER +/–R
ER +/–R
Note 1. The results could be zero (including underflows), a numeral, +1, or –1.
2. ER: The Error Flag (A50003) turns ON and the instruction is not executed.
Md, Md+1, Mr, and Mr+1 must be floating-point data.
Note Refer to page 115 for general precautions on operand data areas.
ER (A50003): Md, Md+1, Mr, and Mr+1 are not floating-point data.
The content of a*DM word is not BCD when set for BCD.
EQ (A50006): The exponent and mantissa of the result are 0.
N (A50008): The result is a negative number.
OF (A50009): The absolute value of the result is greater than the maximum
value that can be expressed for floating-point data.
CIO, G, A, T, C, #, DM
CIO, G, A, T, C, #, DM
CIO, G, A, DM
Multiplicand (floating-point data, 32 bits)
Md
Multiplier (floating-point data, 32 bits)
Mr
Result (floating-point data, 32 bits)
R
Multiplicand
+R –R
ER ER
+/–R +/–R
+R –R
–R +R
Section 5-21
(CVM1 V2)
NaN
ER
301