Altera Floating-Point User Manual
Page 126
Port Name
Type
Required
Description
WIDTH_DATA
Integer
Yes
Specifies the input data width.
If the operation is
INT2FLOAT
, the
WIDTH_DATA
is also
WIDTH_INT
.
If the operation is
FIXED2FLOAT
, the data width value is
WIDTH_INT
+ fractional width.
If the operation is
FLOAT2FIXED
,
FLOAT2INT
or
FLOAT2FLOAT
, the data width value is
WIDTH_EXP_INPUT
+
WIDTH_MAN_INPUT
+
1
.
The available settings are
32
bits,
64
bits or n bits. For n
bits settings, the range is from
4
bits to
64
bits.
WIDTH_EXP_
OUTPUT
Integer
Yes
Specifies the precision of the exponent. If this parameter
is not specified, the default is
8
. The bias of the exponent
is always set to
2
(WIDTH_EXP - 1) -
1
, that is,
127
for
the single-precision format and
1023
for the double-
precision format. The value of
WIDTH_EXP_OUTPUT
must
be
8
for the single-precision format,
11
for the double-
precision format, and a minimum of
11
for the single-
extended precision format. The value of
WIDTH_EXP_
OUTPUT
must be less than the value of
WIDTH_MAN_
OUTPUT
, and the sum of
WIDTH_EXP_OUTPUT
and
WIDTH_
MAN_OUTPUT
must be less than
64
. These settings apply
only to the
FLOAT2FIXED
,
FLOAT2INT
, and
FLOAT2FLOAT
operation modes.
WIDTH_MAN_
OUTPUT
Integer
Yes
Specifies the precision of the mantissa. If this parameter
is not specified, the default is
23
. When
WIDTH_EXP_
OUTPUT
is
8
and the floating point format is single-
precision, the
WIDTH_MAN_OUTPUT
value must be
23
.
Otherwise, the value of
WIDTH_MAN_OUTPUT
must be a
minimum of
31
. The value of
WIDTH_MAN_OUTPUT
must
be greater than the value of
WIDTH_EXP_OUTPUT
, and the
sum of
WIDTH_EXP_OUTPUT
and
WIDTH_MAN_OUTPUT
must
be less than
64
. These settings apply only to the
FLOAT2FIXED
,
FLOAT2INT
, and
FLOAT2FLOAT
operation
modes.
WIDTH_RESULT
Integer
Yes
Specifies the width of the output result. In an
INT2FLOAT
,
FLOAT2FLOAT
, or
FIXED2FLOAT
operation, the result
width is
WIDTH_EXP_OUTPUT
+
WIDTH_MAN_OUTPUT
+
1
.
In a
FLOAT2INT
operation, the result width is the value of
the
WIDTH_INT
parameter.
In a
FLOAT2FIXED
operation, this parameter is the result
width.
The available settings are
32
bits,
64
bits or n bits. For n
bits settings, the range is from
4
bits to
64
bits.
ROUNDING
Integer
Yes
Specifies the rounding mode. The default value is
TO_
NEAREST
. Other modes are not supported.
UG-01058
2014.12.19
ALTFP_CONVERT Parameters
17-11
ALTFP_CONVERT IP Core
Altera Corporation