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605
Floating-point Math Instructions
Section 3-15
Description
–F(455) subtracts the 32-bit floating-point number in Su+1 and Su from the
32-bit floating-point number in Mi+1 and Mi and places the result in R+1 and
R. (The floating point data must be in IEEE754 format.)
If the absolute value of the result is greater than the maximum value that can
be expressed as floating-point data, the Overflow Flag will turn ON and the
result will be output as
±∞
.
If the absolute value of the result is less than the minimum value that can be
expressed as floating-point data, the Underflow Flag will turn ON and the
result will be output as 0.
The various combinations of minuend and subtrahend data will produce the
results shown in the following table.
Note
1.
The results could be zero (including underflows), a numeral, +
∞
, or –
∞
.
2.
With CJ1H-CPU
@@
H-R CPU Units, an undetermined value will be output.
3.
The Error Flag will be turned ON and the instruction will not be executed.
Flags
Precautions
The Minuend (Mi+1 and Mi) and Subtrahend (Su+1 and Su) data must be in
IEEE754 floating-point data format.
Minuend
Subtrahend
0
Numeral
+
∞
–
∞
NaN
0
0
Numeral
+
∞
–
∞
Numeral
Numeral
See note 1.
+
∞
(See note 2.)
–
∞
(See note 2.)
+
∞
–
∞
(See note 2.)
–
∞
(See note 2.)
See note 3.
–
∞
–
∞
+
∞
+
∞
+
∞
See note 3.
NaN
See note 3.
R+1
R
–
Mi
Mi+1
Su
Su+1
Result (floating-point data, 32 bits)
Subtrahend (floating-point data, 32 bits)
Minuend (floating-point data, 32 bits)
Name
Label
Operation
Error Flag
ER
ON if the minuend or subtrahend data is not recognized
as floating-point data.
ON if the minuend or subtrahend is not a number (NaN).
ON if +
∞
is subtracted from +
∞
.
ON if –
∞
is subtracted from –
∞
.
OFF in all other cases.
Equals Flag
=
ON if both the exponent and mantissa of the result are 0.
OFF in all other cases.
Overflow Flag
OF
ON if the absolute value of the result is too large to be
expressed as a 32-bit floating-point value.
Underflow Flag
UF
ON if the absolute value of the result is too small to be
expressed as a 32-bit floating-point value.
Negative Flag
N
ON if the result is negative.
OFF in all other cases.
Содержание SYSMAC CS1D-CPU**
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Страница 185: ...146 List of Instructions by Function Code Section 2 4...
Страница 193: ...154 3 35 4 MOVE BIT MOVBC 568 1274 3 35 5 BIT COUNTER BCNTC 621 1276 3 35 6 GET VARIABLE ID GETID 286 1278...
Страница 1389: ...1350 CJ series Instruction Execution Times and Number of Steps Section 4 2...
Страница 1390: ...1351 Appendix A ASCII Code Table ASCII SP Four leftmost bits Four rightmost bits...
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